p1.ct
Tutorial
Simulating with FluidSIM
Experiments
Excursus
Mathematical models
Various
Tutorial
Welcome to the tutorial: "Simulating with FluidSIM Hydraulics"    The aim of the tutorial is to provide an insight into the simulation of electro-hydraulic systems using the simulation program FluidSIM and practical examples.  It is assumed, that you are familiar with the basic functions and operation of FluidSIM.  
Introduction

p1_1.ct
Tutorial < Experiments
Moving a mass
Experiments
Tutorial
A number of experiments shall now be conducted using the simulation in FluidSIM.
Determination of the hydraulic resistance
Experiments
Moment of inertia
Simulating with FluidSIM

p1_1_1.ct
Tutorial < Experiments < Moving a mass
Horizontal movement of a mass
Vertical movement of a mass
Experiments
Moving a mass
A mass of 300 kg shall be  1. pushed and  2. lifted (mounting angle of cylinder 90°)  by a cylinder-piston.    This experiment shall show, through the choice of different cylinders (settings in the cylinder configurator), how much energy a cylinder requires, in order to move a mass horizontally and vertically.      It shall be shown,    ·	which cylinder is necessary in order to push or lift the 300 kg mass  ·	what effect the mounting angle has over the movement of the same mass and which cylinder is required      
Moving a mass - the problem
Simulating with FluidSIM
Tutorial

p1_1_1_1.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass
Experiments
Moving a mass
Horizontal movement of a mass
Horizontal movement of a 300 kg mass (pushing)
The following circuit serves as an experimental setup.
Simulating with FluidSIM
Tutorial
300 kg

p1_1_1_1_1.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < The double acting cylinder
Experiments
Moving a mass
Horizontal movement of a mass
The double acting cylinder
Cylinder data sheet
First of all, the double acting cylinder, as used in the hydraulic  technology packages from Festo Didactic, shall be evaluated.  This is the modified version of an industrial standard cylinder.     The double acting cylinder with trip cams and two plug-in nipples is fitted to a mounting plate. The machine is fitted to the profile plate via the rotary system using two blue knurled nuts.
The double acting cylinder
Simulating with FluidSIM
Tutorial

p1_1_1_1_10.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Evaluation Part 2
If the pressure is decreased even further (now 1 MPa), then ultimately the piston does not move at all. This is due to the fact that the piston force necessary to move the 300 kg mass diminishes and at a certain level it is insufficient to overcome the static friction.
Evaluation Part 2
Simulating with FluidSIM
Experiments
Moving a mass
Horizontal movement of a mass
Evaluation Part 2
Tutorial
300 kg
1 MPa

p1_1_1_1_2.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Preset cylinder parameters
Experiments
Moving a mass
Horizontal movement of a mass
Preset cylinder parameters
The parameters are set as in the above data sheet. The cylinder parameters can be set in FluidSIM in the property dialog for the cylinder. You can access the properties with a double-click on the relevant cylinder.    ·	piston diameter 16 mm  ·	piston rod diameter 10 mm (see excursus: Calculating the piston rod diameter p1_2_2_1_4)  ·	mounting angle 0° (horizontal mounting position)      Please note: the piston area necessary in order to determine the force of the cylinder piston is calculated automatically by FluidSIM and is displayed in the cylinder configurator under "calculated parameters"). In this case, the piston area is 2.01 (qcm).    
Preset cylinder parameters
Simulating with FluidSIM
Tutorial

p1_1_1_1_3.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < External load and friction
Experiments
Moving a mass
Horizontal movement of a mass
External load and friction
In the test setup, a steel mass shall be moved horizontally along a steel surface. The following parameters need to be set for this external load:    ·	moving mass 300 kg   ·	friction steel on steel  static friction coefficient 0.15  sliding friction coefficient 0.1    
External load and friction
Simulating with FluidSIM
Tutorial

p1_1_1_1_4.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Operating pressure of the pump unit
Experiments
Moving a mass
Horizontal movement of a mass
Operating pressure of the pump unit
The operating pressure of the pump unit is set to 6 MPa (60 bar) by a flow of 2 l/min.   
Operating pressure of the pump unit
Simulating with FluidSIM
Tutorial

p1_1_1_1_5.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Execution
Experiments
Moving a mass
Horizontal movement of a mass
Execution
·	Simulate the circuit diagram and observe the position and velocity of the cylinder piston in the state diagram  ·	Calculate the theoretical piston force of a 16 mm diameter cylinder at 6 MPa (60 bar) system pressure  ·	Calculate whether the force of the 16 mm diameter cylinder is sufficient to move the mass of 300 kg (see Cylinder model - Friction p1_3_13_1_1).    
Execution
Simulating with FluidSIM
Tutorial
300 kg

p1_1_1_1_6.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Evaluation
Experiments
Moving a mass
Horizontal movement of a mass
Evaluation
1.	The cylinder used can move 300 kg.    2.	The theoretical piston force that the cylinder can apply amounts to 1205 N .    3.	Approximately 442 N are necessary to set 300 kg in motion.    
Evaluation
Simulating with FluidSIM
Show solution
Tutorial

p1_1_1_1_7.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Solution
Experiments
Moving a mass
Horizontal movement of a mass
Solution
1.	The theoretical piston force Fth by 6 MPa system pressure is calculated as follows (see theoretical piston force p1_2_2_1).  
2.	In order to the move the mass, we first have to overcome the static friction. For this, the break-away force FB  is calculated as follows (see Cylinder model - Friction p1_3_13_1_1):  
The theoretical piston force amounts to 1205.8 N which is therefore sufficient to set the cylinder piston (and with it, the external mass) horizontally in motion.
Solution  
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Tutorial
3.	The mass remains in motion, because the sliding friction is less than the static friction. The sliding friction force FC, which counteracts the motion, is calculated as follows:  
The inertia of the mass affects the acceleration. The larger the mass to be moved, the lower the acceleration. This needs to be considered for the desired procedural speed. You can find out more about the influence of the moment of inertia in the experiment moment of inertia p1_1_3.

p1_1_1_1_8.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Additional exercise
Experiments
Moving a mass
Horizontal movement of a mass
Additional exercise
Additional exercise
Vary the operating pressure of the pump unit between 6 MPa and 1 MPa. Simulate these circuit diagrams and describe the effects.    Tip: stop the simulation before you change the pressure values, so that the initial situation remains constant when you restart the simulation.    
Simulating with FluidSIM
Tutorial
300 kg

p1_1_1_1_9.ct
Tutorial < Experiments < Moving a mass < Horizontal movement of a mass < Evaluation Part 1
Experiments
Moving a mass
Horizontal movement of a mass
Evaluation Part 1
When the pressure is decreased (here 3 MPa), the piston moves slower. The forces of friction and inertia ensure that the integrated pressure relief valve in the pump unit opens and thus limits the system pressure to the pre-set operating pressure. The lower the setting of the operating pressure, the more hydraulic fluid drains via the pressure relief valve and a lower flow rate is available for the piston movement.
Evaluation Part 1
Simulating with FluidSIM
Tutorial
300 kg
3 MPa

p1_1_1_2.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass
Experiments
Vertical movement of a mass
Moving a mass
Vertical movement of a 300 kg mass (lifting)
The following circuit shows the amended test setup. The cylinder has now been installed vertically (mounting angle of cylinder 90°). The operating pressure is set once again to 6 MPa.    Start the simulation. The cylinder piston does not extend. Obviously, the piston force is less than the force of gravity on the mass to be lifted.
Simulating with FluidSIM
Tutorial
300 kg

p1_1_1_2_1.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Choice of cylinder
Experiments
Vertical movement of a mass
Moving a mass
A cylinder needs to be chosen with a piston force that is greater than the force of gravity on the mass to be lifted. Bear in mind, that friction does not play a part when vertically lifting a mass (cos(90°)=0, see cylinder model - friction p1_3_13_1_1).  The following steps need to be performed when choosing a cylinder:    ·	calculate the force of gravity on the mass to be lifted.  ·	define, with the use of data sheets or calculation, (see excursus Calculating the theoretical and effective piston force p1_2_2) the minimum piston diameter necessary to lift the mass at an operating pressure of 6 MPa.      
Choice of cylinder
Choice of cylinder
Simulating with FluidSIM
Tutorial

p1_1_1_2_2.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Evaluation
Experiments
Vertical movement of a mass
Moving a mass
Evaluation
Change the cylinder parameters in accordance with your calculations and simulate the circuit diagram.    Theoretically, a minimum of 25 mm piston diameter by 6 MPa is necessary to lift 300 kg. In comparison, a 10 mm piston diameter is sufficient to move the same mass with an external friction of 0.1 - 0.15.    However, in practice and in the simulation with FluidSIM, static friction effects occur at the cylinder piston causing the cylinder piston not to extend. Therefore an approx. 10% larger piston diameter of 28 mm is chosen.    
Evaluation
Simulating with FluidSIM
Show solution
Tutorial
300 kg

p1_1_1_2_3.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Solution
Experiments
Vertical movement of a mass
Moving a mass
Solution
The force of gravity FW of a mass m of 300 kg is calculated using the acceleration due to gravity g ˜ 9.81 m/s² with the following formula:
The required piston area A is calculated as follows:
Solution
Simulating with FluidSIM
Tutorial
The piston diameter d arises from:

p1_1_1_2_4.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Function testing
Experiments
Vertical movement of a mass
Moving a mass
Function testing
Verify the cylinder parameter settings and simulate the circuit diagram.
Function testing
Simulating with FluidSIM
300 kg
Tutorial

p1_1_1_2_5.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Additional exercise
Experiments
Vertical movement of a mass
Moving a mass
Additional exercise
Vary the operating pressure of the pump unit between 6 MPa and 4 MPa. Simulate these circuit diagrams and describe the effects.    Tip: stop the simulation before you change the pressure values, so that the initial situation remains constant when you restart the simulation.    
Additional exercise
Simulating with FluidSIM
Tutorial
300 kg

p1_1_1_2_6.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Evaluation Part 1
Experiments
Vertical movement of a mass
Moving a mass
Evaluation Part 1
When the pressure is decreased, the piston moves slower. The forces of weight, friction and inertia ensure that the integrated pressure relief valve in the pump unit opens and thus limits the system pressure to the pre-set operating pressure. The lower the setting of the operating pressure, the more hydraulic fluid drains via the pressure limitation valve and a lower flow rate is available for the piston movement.
Evaluation Part 1
Simulating with FluidSIM
Tutorial
300 kg

p1_1_1_2_7.ct
Tutorial < Experiments < Moving a mass < Vertical movement of a mass < Evaluation Part 2
Experiments
Vertical movement of a mass
Moving a mass
Evaluation Part 2
If the pressure is decreased even further, then ultimately the piston does not move at all. This is due to the fact that the piston force necessary to move the 300 kg mass diminishes and at a certain level it is insufficient to overcome the force of gravity.
Evaluation Part 2
Simulating with FluidSIM
Tutorial
300 kg

p1_1_2.ct
Tutorial < Experiments < Determination of the hydraulic resistance
Determination of the hydraulic resistance
Although it is possible in FluidSIM to allocate a hydraulic resistance directly to every valve (see Orifice resistance p1_2_1_4_4_1), it is also possible to determine this resistance with the following test set up. The resistance RH  specifies the increase in the quadratic Dp-q-characteristic Dp = RH ·q2  and can be calculated with a measured flow rate q and pressure loss Dp as follows:
Experiments
Determination of the hydraulic resistance - problem and test set up
Simulating with FluidSIM
Tutorial
The hydraulic resistance of the directional valve shall now be determined. The resistance relates to a metering edge.
The delivery rate of the pump unit is set to 10 l/min.

p1_1_2_1.ct
Tutorial < Experiments < Defining the hydraulic resistance < Execution
Start the simulation and read off the pressures at the manometer and the flow rate at the flow-meter.
Execution
Experiments
Defining the hydraulic resistance
Execution
Simulating with FluidSIM
Show evaluation
Tutorial

p1_1_2_2.ct
Tutorial < Experiments < Defining the hydraulic resistance < Evaluation
A pressure loss of Dp = 1.65 MPa - 0.01 MPa = 1.64 MPa occurs at the metering edge. The hydraulic resistance RH of the directional valve can now be calculated as follows:
Evaluation
Evaluation
Simulating with FluidSIM
Tip: the simulation must be terminated with "Execute - Stop" before you can open the directional valve's properties dialog. You are now in the edit mode. In the simulation mode, you would switch the valve if you clicked on it.  
Tutorial
Defining the hydraulic resistance
Experiments
After you have stopped the simulation, you can verify the calculated value in the directional valve's dialog box.  Open the properties window for the directional valve with a double click. There you can read the settings for the hydraulic resistance.  

p1_1_3.ct
Tutorial < Experiments < Moment of inertia
Experiments
Moment of inertia
A mass of 10 kg and 500 kg resp. shall be moved horizontally by a cylinder piston. The experiment shall show the effects that inertia have on the movement of the cylinder piston and the adjacent pressures. Then     ·	on the basis of the cylinder pistons' behavior (position, speed and acceleration in the state diagram), the moment of inertia shall be demonstrated and traced,  ·	the adjacent pressures shall be observed,  ·	measures shall be taken to prevent the adjacent pressures from falling below the vapour pressure.        
Moment of inertia - the problem  
Simulating with FluidSIM
Tutorial

p1_1_3_1.ct
Tutorial < Experiments < Moment of inertia < Law of Inertia
Experiments
The law of inertia defines the term inertia as follows:    "An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force."    The cause of every change of movement (acceleration) is a force. The relationship between force, mass and acceleration is described by the following equation:    
Law of Inertia
i.e. the force is proportional to the product of the mass times the acceleration. It follows that, the larger the mass, the greater the force must be in order to achieve the same acceleration.    
Moment of inertia
Law of Inertia
Simulating with FluidSIM
Tutorial

p1_1_3_10.ct
Tutorial < Experiments < Moment of inertia < Increasing the moving mass
Experiments
Increasing the moving mass
Increasing the moving mass
Moment of inertia
Simulating with FluidSIM
Tutorial
In the following the moving mass will be increased from 10 kg to 500 kg.    Simulate the circuit diagram and observe in the state diagram, the position, velocity and acceleration of the cylinder piston during the extension.    Describe and explain the result.

p1_1_3_11.ct
Tutorial < Experiments < Moment of inertia < Evaluation
Experiments
Evaluation
The cylinder piston again extends with an oscillating speed and acceleration. Due to the counteracting force, the maximum speed remains sufficiently low and the inlet pressure does not fall below the vapour pressure. In contrast to the previous experiment, the frequency of oscillation and the acceleration amplitudes are significantly lower.     From the equation (see Law of Inertia p1_1_3_1)
Evaluation
Moment of inertia
Simulating with FluidSIM
Tutorial
follows
This means that by increasing the mass, the acceleration, with a constant force, is reduced. As the operating pressure is limited to 6 MPa (60 bar), then the theoretical piston force p1_2_2 is limited to 1206 N and with it the acceleration to approx. 2.4 m/s2 . The acceleration is significantly lower than in the previous experiment with 10 kg moving mass. This leads to a reduction in the oscillation frequency.

p1_1_3_2.ct
Tutorial < Experiments < Moment of inertia < Test set up
Test set up
The following circuit diagram serves as a test setup:
Moment of inertia
Test set up
Simulating with FluidSIM
Tutorial
Experiments

p1_1_3_3.ct
Tutorial < Experiments < Moment of inertia < Preset cylinder parameters
Experiments
Moment of inertia
Preset cylinder parameters
The cylinder parameters can be set in FluidSIM in the property dialog for the cylinder. You can access the properties with a double-click on the relevant cylinder icon. The parameters are set as follows:            ·	piston diameter 16 mm  ·	piston-rod diameter 10 mm   ·	mounting angle 0° (horizontal mounting position)      Please note: the piston area required to define the force of the cylinder piston is automatically calculated by FluidSIM and displayed in the cylinder configurator under "calculated parameters". In this case, the piston area is 2.01 (qcm).  
Preset cylinder parameters
Simulating with FluidSIM
Tutorial

p1_1_3_4.ct
Tutorial < Experiments < Moment of inertia < Setting the moving mass
Experiments
Moment of inertia
Setting the moving mass
The moving mass is set at 10 kg. For simplification and clarification, the static and the sliding-friction, which arises by the horizontal movement according to the material, will not be considered during this experiment.
Setting the moving mass
Simulating with FluidSIM
Tutorial

p1_1_3_5.ct
Tutorial < Experiments < Moment of inertia < Pump unit settings
Experiments
Moment of inertia
Pump unit settings
The pump unit delivers 2 l/min, as long as the operating pressure remains below 6 MPa (60 bar).
Pump unit settings
Simulating with FluidSIM
Tutorial

p1_1_3_6.ct
Tutorial < Experiments < Moment of inertia < Execution
Execution
Simulate the circuit diagram and observe in the state diagram the position, velocity, acceleration and the adjacent inlet pressure at the cylinder during the extension.    Describe and explain the result.  
Execution
Moment of inertia
Simulating with FluidSIM
Tutorial
Experiments

p1_1_3_7.ct
Tutorial < Experiments < Moment of inertia < Evaluation
Experiments
Evaluation
The cylinder piston does not extend with a constant velocity, instead the velocity oscillates at approx. 0.17 m/s with attenuating amplitude. This is also true for the acceleration and inlet pressure at the cylinder. In doing so, it causes an additional undesired effect. The pressure occasionally falls below the vapour pressure of the hydraulic fluid, which can lead to cavitation effects (see Ccavitation und vapour pressure p1_2_1_5).    Shortly after the simulation starts, the pressure increases in the left cylinder chamber and the piston accelerates to approx. 0.3 m/s. The counteracting force is primarily just the frictional force of the cylinder piston, as the right chamber is directly connected to the tank via the directional valve and can therefore only build up a low counter pressure. At 0.3 m/s approx. 3.62 l/min flow in to the left cylinder chamber (q=A·v). However only 2 l/min return from the pump unit. Therefore the inlet pressure falls below the vapour pressure. Only when the cylinder has been braked so far that more oil returns than drains, does the pressure increase and the cylinder accelerates again. This oscillation is absorbed further and further through the friction losses.     The moving cylinder mass is mounted between two oil reservoirs. The changes of movement of the cylinder mass and the pressure changes in the oil reservoir, are carried out at different speeds and therefore the complete system is capable of oscillation. In control engineering this is also known as a second order system (PT2-System) [1] p1_4_2.    
Evaluation
Moment of inertia
Simulating with FluidSIM
Tutorial

p1_1_3_8.ct
Tutorial < Experiments < Moment of inertia < Inserting a counter force
Experiments
Inserting a counter force
In the previous experiment, the inlet pressure occasionally fell below the vapour pressure of the hydraulic fluid. This undesirable effect can be avoided, when the back pressure in the right cylinder chamber is so high that the procedural speed remains slow enough and a sufficient volumetric flow can return.    The simplest method is to install a throttle valve in the cylinder discharge. A similar effect can be achieved with pressure relief valves, flow control valves or complicated circuitry methods.    The hydraulic resistance at complete opening is 0.045 MPa/(l/min)2 and the opening level is set to 10%.     Simulate the circuit diagram and describe the result.  
Inserting a counter force
Moment of inertia
Simulating with FluidSIM
Tutorial

p1_1_3_9.ct
Tutorial < Experiments < Moment of inertia < Evaluation
Evaluation
The cylinder piston extends with an oscillating velocity and acceleration. Due to the counteracting force, the maximum speed remains sufficiently low and the inlet pressure does not fall below the vapour pressure.
Evaluation
Simulating with FluidSIM
Experiments
Moment of inertia
Tutorial

p1_2.ct
Tutorial < Excursus
Calculating the theoretical|and effective piston force
Excursus
Pressure definitions
The following excursus gives a deeper insight into the physical relationships that occurred in the previous experiments.
Excursus
Physical Essentials
Properties of hydraulic fluids
Flow rate models
Simulating with FluidSIM
Pressure transmission
Tutorial
Cavitation
Vapour pressure
Compressibility of hydraulic fluids
Pressure energy

p1_2_1.ct
Tutorial < Excursus < Physical Essentials
Excursus
Physical Essentials
Hydraulics is defined as the creation of forces and movements through hydraulic fluids.  The hydraulic fluids are hereby the energy transfer medium [3] p1_4_2.    Hydraulics is divided into the areas hydrostatic - exertion of force through pressure times area - and  hydrodynamic - exertion of force through mass times acceleration.    These facts are expressed by the following equations:    Hydrostatic:
Physical Essentials
Simulating with FluidSIM
Tutorial
transposed with p
Hydrodynamic:
with    	F	 = force in Newton [N]  	p	 = pressure in Pascal [Pa]  	A	 = area in square meter [m2]  	M	 = mass in kilogram [kg]  	a	 = acceleration in meter per second squared [m/s2]    

p1_2_1_1.ct
Tutorial < Excursus < Physical Essentials < Pressure definitions
Excursus
Physical Essentials
The unit of measurement for pressure is 1 Pa (see SI-units p1_4_1). Various pressure sizes are used for which different descriptions are generally in use [2] p1_4_2. The most important descriptions, as recommended in the DIN standard 1314, are:    ·	Absolute pressure  	the absolute pressure applies to absolute zero (vacuum).    ·	Atmospheric pressure  	the atmospheric pressure is the absolute pressure, as ascertained at the measuring-point. This is not constant and is dependent upon geographical position or weather.    ·	Excess pressure  	the excess pressure is the pressure ascertained at the measuring-point, in relation to the atmospheric pressure as zero point. Gauges in pneumatic systems usually display the excess pressure. Excess pressure is also known as effective pressure or relative pressure.    In hydraulics the pressures are generally denoted as excess pressure.    
Pressure definitions
Pressure definitions
Simulating with FluidSIM
Tutorial

p1_2_1_2.ct
Tutorial < Excursus < Physical Essentials < Pressure transmission
Excursus
Physical Essentials
If a force F is exerted over an area A on an enclosed fluid, then a pressure p arises that spreads across the complete fluid (Pascal's Law). The same pressure is exerted at every point of the enclosed system (see illustration). The form of the container is in this case unimportant.
Pressure transmission
Pressure transmission
Simulating with FluidSIM
Tutorial

p1_2_1_3.ct
Tutorial < Excursus < Physical Essentials < Properties of hydraulic fluids
Excursus
Properties of hydraulic fluids
Properties of hydraulic fluids
Simulating with FluidSIM
Physical Essentials
Tutorial
Viscosity
Density

p1_2_1_3_1.ct
Tutorial < Excursus < Physical Essentials < Properties of hydraulic fluids < Density
Excursus
Because of the low compressibility of hydraulic fluids, the Density r is significantly dependent upon the temperature. Density is specified in kg/m3 . FluidSIM calculates using the parameters of an oil from type HLP, whose density is 870 kg/m3 at 15°C [8] p1_4_2. Temperature changes are not taken into account by FluidSIM and the density is therefore assumed constant.  
Density
Density
Properties of hydraulic fluids
Simulating with FluidSIM
Physical Essentials
Tutorial

p1_2_1_3_2.ct
Tutorial < Excursus < Physical Essentials < Properties of hydraulic fluids < Viscosity
Excursus
The tenacity or viscosity of a hydraulic fluid is defined as the resistance that is opposed to a displacement of adjacent fluid layers. It is a material property of the fluid and basis for the calculation of hydraulic resistances  [8] p1_4_2. One differentiates between dynamic viscosity h and kinematic viscosity n. Viscosity is determined with standard procedures e.g. as per DIN 51562 with the "Ubbelohde-Viscometer" and as per DIN 51561 with the "Vogel-Ossag-Viscometer". For the detemination of kinematic viscosity, the "Ball viscometer" can also be utilised. With these procedures the viscosity values in a wide area can be very precisely determined [3] p1_4_2. The speed is measured with which a body, under the influence of gravity, sinks in fluid. The measured value is equivalent to the dynamic viscosity.    To attain the kinematic viscosity n , the dynamic viscosity h must be divided by the density r of the fluid:
Viscosity
Viscosity
Properties of hydraulic fluids
Simulating with FluidSIM
Physical Essentials
Tutorial
In oil hydraulics the units mPa×s (milli Pascal seconds) are frequently used for the dynamic viscosity and mm2/s or cSt (centi Stokes) resp. for the kinematic viscosity.    Viscosity is a material property that is dependent upon temperature and pressure. The pressure dependence is often neglected. The viscosity of fluids decreases by increasing temperature - by gases the viscosity increases. In FluidSIM the kinematic viscosity is assumed to be a constant 22 mm2/s (cSt).     
Ball viscometer  

p1_2_1_4.ct
Tutorial < Excursus < Physical Essentials < Flow rate models
Excursus
We differentiate between laminar flow (lamina = layer) and turbulent flow. If a fluid flows along a wall then the layer adjacent to the wall adheres to it owing to the adhesion forces of the fluid.
Flow rate models
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
By the laminar flow, the hydraulic fluid moves in the pipe in orderly, cylindrical layers. Thereby the inner fluid layers have a greater velocity than the outer layers. If the flow rate of the hydraulic fluid increases then, at a certain velocity (known as the critical velocity), the fluid particles do not move in orderly layers. The fluid particles in the middle of the pipe escape to the side. Thus the fluid particles influence and obstruct themselves mutually, vortices are formed, the flow becomes turbulent. As a consequence the main flow is deprived of energy.  

p1_2_1_4_1.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Reynolds-Number
Excursus
The significant value for the flow form is the dimensionless Reynolds-number Re. It describes the ratio between inertia forces and viscous forces. It is dependent upon the fluid velocity w [m/s], the characteristic length l [m] or "hydraulic diameter" DH [m] and the kinematic fluid viscosity n [m2/s]:    
Reynolds-Number
Reynolds-Number
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
In connection with flow resistances, the characteristic length l as hydraulic diameter DH is defined such that DH conforms to a circular cross-section with the geometric diameter d of the circle.  
The area of the flow cross-section is denoted with A and the wetted circumference with U. The following applies to the circular cross-section:  
For a narrow gap with a low height h as opposed to the width b the following applies:  
The critical Reynolds-Number Recrit indicates the value at which a transition from laminar flow to turbulent flow occurs. The critical Reynolds-Number is not constant, instead it depends upon the component through which the oil flows. The transition from laminar to turbulent flow occurs in a smooth pipe at approx.  Recrit = 2300. This transition is reached with other flow resistances at even smaller Reynolds-numbers of approx. Re = 200.     A turbulent flow is not immediately laminar, if it remains below Recrit. The laminar range is not reached again before ½ Recrit .  

p1_2_1_4_2.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Friction, Heat, Pressure loss
Excursus
Friction occurs in all perfused devices and pipelines of a hydraulic system.    This is primarily the friction at the pipeline walls (exterior friction). In addition there is the friction between the fluid layers (interior friction). The friction leads to a temperature rise in the hydraulic fluid and, consequently, in the components too. As a result of this heat development, the pressure falls in the system and thereby reduces the effective pressure at the drive section. The component represents a hydraulic resistance.    The relationship between volumetric flow and pressure loss is essentially dependent upon whether a laminar or turbulent flow exists in the observed component. The Reynolds-number (see Reynolds-number p1_2_1_4_1) serves as measure for the flow type.  
Friction, Heat, Pressure loss
Friction, Heat, Pressure loss
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial

p1_2_1_4_3.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Laminar Flow
Excursus
A laminar flow is characterised by a linear relationship between flow rate q and pressure loss Dp at the observed throttle point (see illustration).  
Laminar Flow
Laminar Flow
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial

p1_2_1_4_3_1.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Laminar Flow < Resistance of components to laminar flow
Excursus
The following relationship, which has been derived with the assistance of the Hagen-Poiseuille Law, applies to a laminar flow through a circular smooth pipe or a throttle [8] p1_4_2: 
Resistance of components to laminar flow
Laminar Flow
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
Resistance of components to laminar flow
The following applies to the flow through a rectangular gap:
with    	q	 = flow rate [m3/s]  	Dp	 = pressure loss at the throttle point [Pa]  	h	 = dynamic viscosity [Pa×s]  	l	 = throttle point length [m]  	r	 = throttle point radius [m]  	b	 = gap width [m]    Combining all component parameters to one parameter results in the following relationship:
The volumetric flow is therefore directly proportional to the pressure difference and inversely proportional to the dynamic viscosity. As the viscosity is very dependent on temperature, so the flow property of the laminar flow is also dependent upon temperature.     In FluidSIM, the pipelines (connections between the components) are modeled ideally and therefore no pressure losses occur in the pipelines. A pressure loss can, however, be simulated by using a throttle as resistance.

p1_2_1_4_4.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Turbulent Flow
Excursus
A turbulent flow on the other hand is characterized by a quadratic relationship between flow rate q and pressure loss Dp. For example, the pressure loss in the valves can be taken from the manufacturers Dp-q-characteristics.    
Turbulent Flow
Turbulent Flow
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
The relationship between flow rate and pressure loss is often known as root-shaped. In this case, only the axes in the graph have been exchanged.

p1_2_1_4_4_1.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Turbulent Flow < Orifice Resistance
Excursus
The following relationship, which has been derived with the assistance of Bernoulli's equation, applies to the flow rate through orifices [8] p1_4_2:    
Orifice Resistance
Turbulent Flow
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
Orifice Resistance
with    	q	 = flow rate [m3/s]  	Dp	 = pressure loss at the orifice [Pa]  	aD	 = flow coefficient [-]  	A	 = orifice cross-section area [m2]  	r	 = oil density [kg/m3]     According to the above equation, the volumetric flow through orifice-shaped, technical throttles is denoted with a flow coefficient aD, which is a function of the Reynolds-Number. The determination of the flow coefficient has been the subject of very extensive investigations, as every cross-section shape possesses different values regarding the geometry of the leading edge.     While the volumetric flow through gaps and throttles is directly proportional to the pressure difference Dp and inversely proportional to the dynamic viscosity, for the orifices there is a root-shaped dependence upon the pressure difference. Orifices are preferable to throttles as technical resistances, while the flow law is predominantly viscosity dependent and therefore also temperature dependent.   Combining all component parameters to one parameter k (hydraulic conductance) results in the following relationship:   

p1_2_1_4_4_2.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Turbulent Flow < Setting the hydraulic resistance in FluidSIM
Excursus
In FluidSIM the Dp-q-characteristics of valves can be specified either graphically or through the definition of a hydraulic resistance RH.  The oil density is assumed to be a constant 870 kg/m3. For this purpose a formula equivalent to the previous equation
Setting the hydraulic resistance in FluidSIM
Turbulent Flow
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
Setting the hydraulic resistance in FluidSIM
By specifying a nominal volume flow qn and a nominal pressure loss Dpn then RH can be calculated as follows:
Double click on the orifice to open its properties dialog.   Set the value of the resistance by a left mouse click in the graphic area   to place a point on the characteristic curve.     Note: The focus of the parabola is at the origin and hence a second   point determines the entire function.  
is used:

p1_2_1_4_4_3.ct
Tutorial < Excursus < Physical Essentials < Flow rate models < Turbulent Flow < Resistance of continuous valves
Excursus
The flow rate model specified under resistance of orifices p1_2_1_4_4_1 is also used for the modeling of the flow rate of slide valves [1, 4] p1_4_2. By servo valves and control valves,  the aim is to achieve a linear relationship between the slide distance x and the released area A . This is technically implemented by the use of rectangular shaped leading edges. The flow rate and the slide distance doubles when the pressure is kept constant. The following equation describes this relationship:
Resistance of continuous valves
Turbulent Flow
Flow rate models
Simulating with FluidSIM
Physical Essentials
Tutorial
Resistance of continuous valves
All component-specific properties and the oil density are combined in parameter B.
with    	q	 = flow rate [m3/s]  	Dp	 = pressure loss [Pa]  	aD	 = flow coefficient [-]  	x	 = slide distance [m]  	d	 = orifice diameter [m]  	r	 = oil density [kg/m3]    Triangular-shaped leading edges (V-slots) are often deployed by proportional-valves. The flow rate quadruples and the slide distance doubles when the pressure is kept constant. The following equation describes this relationship:
Besides the type of leading edge and the parameter B , FluidSIM also takes a laminar leakage and the overlap of the leading edge (null overlap, negative und positive overlap) into account. The parameter B is specified in the form of a hydraulic resistance or a nominal volume flow and nominal pressure loss resp. at a fully opened leading edge.

p1_2_1_5.ct
Tutorial < Excursus < Physical Essentials < Cavitation
Excursus
If the flow velocity of the oil at the throttle point increases, then kinetic energy is required. The kinetic energy is withdrawn from this pressure energy. This can result in a pressure loss in the negative pressure area at this throttle point. From a negative pressure of -30 kPa (-0.3 bar) onwards, dissolved air escapes from the oil. Gas bubbles form. If the pressure increases again due to a speed reduction, the oil rushes into the gas bubbles. Due to the high pressure after the throttle point, very high temperatures develop caused by the collapse of the bubbles through the air compression. This process is called cavitation (cavitare = hollow out). This can lead to the spontaneous combustion - similar to that in a diesel motor (diesel effect) - of the oil/air mix in the bubbles. At the site of the cross-section extension small particles break away from the material. This leads to material fatigue and often also to destruction.      
Cavitation  
Cavitation
Simulating with FluidSIM
Physical Essentials
Tutorial

p1_2_1_6.ct
Tutorial < Excursus < Physical Essentials < Vapour pressure
Excursus
Cavitation can however occur in a different connection. Tractive force or forces of inertia at the cylinder piston, can cause pressures to fall below the vapour pressure of the utilized oil and thus induce  cavitation effects.  FluidSIM calculates with a relative vapour pressure of  -0.999×105 Pa (-0.999 bar).  
Vapour pressure
Vapour pressure
Simulating with FluidSIM
Physical Essentials
Tutorial

p1_2_1_7.ct
Tutorial < Excursus < Physical Essentials < Compressibility of hydraulic fluids
Excursus
Oil is compressible. If a fluid is exposed to pressure then its volume decreases due the dissolved gases therein. The compressible range amounts to 1-3% of the output volume. The pressure energy is low due to the low compressibility of the hydraulic fluid, i.e. the relatively small DV. At a pressure of 100 bar, DV amounts to approx. 1% of the output volume. There follows a calculation based on these values.
Compressibility of hydraulic fluids
Compressibility of hydraulic fluids
Simulating with FluidSIM
Physical Essentials
Tutorial
with    	W	 = work [J]  	p	 = pressure [Pa]  	DV	 = volume difference [m3]        

p1_2_1_8.ct
Tutorial < Excursus < Physical Essentials < Pressure energy
Excursus
Pressure energy results from the pressure that the fluid opposes to the compression.     All materials can be compressed. This means, that if the initial pressure p0 is increased by the value Dp, then the initial volume V0 is decreased by the value DV. This compressibility is increased by the gases dissolved in the oil (up to 9 %) and the increasing temperature. The characteristic for this is the bulk modulus BOil. The compressibility of the oil is described mathematically through:  
Pressure energy
Pressure energy
Simulating with FluidSIM
Physical Essentials
Tutorial
with    	DV	 = volume difference [m3]  	V	 = initial volume [m3]  	BOil	 = bulk modulus [Pa]  	Dp	 = pressure difference [Pa]    The bulk modulus is not constant, rather it is dependent upon pressure, oil type, oil temperature and the undissolved air in the oil. The components surrounding the oil also expand under pressure. It has therefore become widely acceptable to combine all elasticities involved in the pressure build-up in one variable, the equivalent bulk modulus B'Oil. The apostrophe is used to differentiate between the bulk modulus of the oil and the equivalent bulk modulus; it does not describe a derivative of the value BOil. The equivalent bulk modulus B'Oil is generally not constant and takes various parameters into account such as: pressure; temperature; the proportion of dissolved air and the elasticity of the containers [1] p1_4_2.    FluidSIM calculates with a constant equivalent bulk modulus of 1.4×109 Pa.  

p1_2_1_8_1.ct
Tutorial < Excursus < Physical Essentials < Pressure energy < Pressure build-up in a reservoir
Excursus
In FluidSIM models, lumped volumes are used to calculate the fluctuations in pressure over a period of time. This means that the oil volumes in the component connections are combined. Furthermore, temperature fluctuations are not considered, i.e. the temperature is assumed to be a constant 293.15 K (20 °C).  If oil flows under pressure in an enclosed reservoir V, then the pressure in this reservoir changes. This is described with the following differential equation [1] p1_4_2:  
Pressure build-up in a reservoir
Simulating with FluidSIM
Physical Essentials
Tutorial
with    	p	 = pressure change [Pa/s]  	B'Oil	 = equivalent bulk modulus [Pa]  	V	 = volume [m3]  	q	 = volumetric flow [m3/s]    The equation describes the chronological fluctuations in the pressure p in the volume V dependent upon the chronologically fluctuating volumetric flow q.    The bulk modulus B'Oil is dependent upon pressure, temperature and the proportion of undisssolved air in the hydraulic fluid (see compressibility of hydraulic fluids p1_2_1_7). FluidSIM disregards this dependence and calculates with a constant equivalent bulk modulus of 1.4×109 Pa and a volume V= 10-4 m3 (0.1 l).    
Pressure build-up in a reservoir
Pressure energy

p1_2_1_8_2.ct
Tutorial < Excursus < Physical Essentials < Pressure energy < Comparison: calculation und simulation
In the following, the differential equation for the calculation of the pressure build-up shall be verified using a simple test set-up.    It is assumed that in a component port there is a constant volumetric flow of q = 0.1 l/min (10-4/60 m3/s) without drainage. According to the specified differential equation the pressure increase per second is:    
Comparison: calculation und simulation
Simulating with FluidSIM
The calculated pressure increase can easily be verified in FluidSIM. For this purpose, a simplified pump unit is necessary, with a blind plug over the port. An operating pressure of 6 MPa and a delivery rate of 0.1 l/min has to be specified. Start the simulation in single-step mode and display the pressure values at the port. Carry out single steps until the operating pressure has reached 6 MPa. According to the example calculation, the operating pressure is attained in  
Comparison: calculation und simulation
In the simulation a pressure of 5.99 MPa is attained precisely within this time. As before reaching the operating pressure an internal pressure-relief valve in the pump unit opens, less than 0.1 l/min flow into the reservoir and 6 MPa is first reached after 0.306 s.  
Note: the pressure and flow rate values and their units can be displayed using the option "View - Quantity values".  The elapsed simulation time is displayed below right in the status line of the FluidSIM main window.  
Excursus
Physical Essentials
Tutorial
Pressure energy

p1_2_2.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force
Excursus
Calculating the theoretical and effective piston force
The exerted piston force of an actuator is dependent upon pressure, the cylinder piston diameter and the frictional resistance of the sealing elements. The model used in FluidSIM is described in detail under cylinder model p1_3_13.        
Theoretical piston force
Effective piston force
Calculating the theoretical and effective piston force
Simulating with FluidSIM
Tutorial

p1_2_2_1.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force < Theoretical piston force
Excursus
Friction and external influences (forces) are not taken into account when calculating the theoretical piston force. The back pressure during the forward-stroke and the reverse-stroke is assumed to be zero (atmospheric pressure p1_2_1_1). The simplified formula for the theoretical piston force results from the equilibrium of forces as follows:    		Fth = p · A with    
Calculating the theoretical and effective piston force
Theoretical piston force
Theoretical piston force
Simulating with FluidSIM
Tutorial
 p1_2_1_1Fth theoretical piston force  A = A1 useable (effective) piston area during the forward-stroke  A = A2 useable (effective) piston-ring area during the reverse-stroke  p = p1 operating pressure as excess pressure during the forward-stroke  p = p2 operating pressure as excess pressure during the reverse-stroke  
 p1_2_1_1Using the piston diameter dP and the piston-rod diameter dR,, then the piston area A1 and the piston-ring area A2 can be calculated as follows:  

p1_2_2_1_1.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force < Theoretical piston force < Example
Excursus
The effective piston area by a piston diameter of 16 mm (0.016 m) is:  
Theoretical piston force
The following applies for the piston-ring area with a piston-rod diameter of 10 mm (0.01 m):
The cylinder configurator in FluidSIM automatically calculates the theoretically useable piston area and the piston-ring area under „calculated parameters".
Example
Open the properties dialog of the cylinder with a double-click and vary the values (under „parameters") for the piston diameter and the piston-rod diameter.  Observe hereby, how the piston area and piston-ring area are derived.  
Example
Simulating with FluidSIM
Calculating the theoretical and effective piston force
Tutorial

p1_2_2_1_2.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force < Theoretical piston force < Exercise
Excursus
What is the theoretical piston force of the following cylinder during the forward- and the reverse-stroke at a pressure of 0.6 MPa (6 bar)?
Show solution
Exercise
Open the properties dialog of the cylinder with a double-click and read off the piston- and piston-ring values under "Parameters".
Exercise
Simulating with FluidSIM
Calculating the theoretical and effective piston force
Theoretical piston force
Tutorial

p1_2_2_1_3.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force < Theoretical piston force < Solution
Excursus
Forward-stroke:     p1 = 6000000 Pa   A1 = 0.00020106 m²   Fth = p · A = 6000000 Pa · 0.00020106 m² ˜ 1206.4 N      Reverse-stroke:     p2 = 6000000 Pa   A2 = 0.000122519 m²   Fth = p · A = 6000000 Pa · 0.000122519 m² ˜ 735.1 N      Note:  The theoretical piston force of a cylinder during the forward- and the reverse-stroke can often be found in its' data sheet.   
Solution
Solution
Simulating with FluidSIM
Calculating the theoretical and effective piston force
Theoretical piston force
Tutorial

p1_2_2_1_4.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force < Theoretical piston force < Calculating the piston-rod diameter
Excursus
Calculating the piston-rod diameter
If the piston-rod diameter dR  is not explicitly specified in the data sheet, then it can be calculated from the theoretical force during the reverse-stroke using the following formula:  
The following calculation results for piston-rod diameter dR  of the cylinder in the previous example:  
Calculating the piston-rod diameter
Simulating with FluidSIM
Calculating the theoretical and effective piston force
Theoretical piston force
Tutorial

p1_2_2_2.ct
Tutorial < Excursus < Calculating the theoretical and effective piston force < Effective piston force
Excursus
In practice, the effective piston force is of importance. The frictional resistance of the cylinder needs to be taken into account when calculating the effective piston force. Under normal operating conditions, the frictional force (frictional resistance of the sealing elements) used for the estimation of the effective piston force, can be assumed to be approx. 10% of the theoretical piston force. FluidSIM uses a more complex friction model for the dynamic simulation (see cylinder model p1_3_13).    The following formula can be used to estimate the effective piston force:    Double acting cylinder (forward stroke):    	Feff = A1 · p1 - FF with    FF frictional force (approx. 10% from Fth)     Double acting cylinder (reverse stroke):    	Feff = A2 · p2 - FF with    FF frictional force (approx. 10% from Fth)    Single acting cylinder with return spring (forward stroke):    	Feff = A1 · p1 - FF - FS with    FF frictional force (approx. 10% from Fth)  FS return spring force  
Effective piston force
Effective piston force
Relationship between piston diameter and piston force
Simulating with FluidSIM
Calculating the theoretical and effective piston force
Tutorial

p1_3.ct
Tutorial < Mathematical models
Model of the 2-way flow control valve
Mathematical models
Model of the pump unit
Mathematical models
The most important physical models of the components used in FluidSIM are described below.
Model of the 3-way flow control valve
Model of the pump
Model of the hydraulic reservoir
Flow rate model of components with|a constant cross-section
Model of the hydraulic line
Model of the configurable way valve
Simulating with FluidSIM
Tutorial
Simulation methods
Model of the flow dividing valve
Model of the piloted pressure relief valve
Model of the piloted pressure regulating valve
Model of the cylinder
Model of the rotary drive
Flow rate model of components with|pressure dependent cross-section

p1_3_1.ct
Tutorial < Mathematical models < Model of the pump unit
Model of the pump unit
Mathematical models
The pump unit model takes three parameters into account:    ·	operating pressure  ·	flow  ·	internal leakage    As long as the operating pressure has not been reached, the unit constantly supplies the pre-set flow. The pressure results from the resistance of the attached components. Close to the operating pressure, the delivery flow rate drops until, at operating pressure, it reaches exactly zero.    If an internal leakage greater than zero is specified, then the delivery rate is reduced by the leakage flow (rate). The leakage flow is modeled as a laminar flow p1_2_1_4_3.
Model of the pump unit
Simulating with FluidSIM
Tutorial

p1_3_10.ct
Tutorial < Mathematical models < Model of the flow dividing valve
Model of the flow dividing valve
Mathematical models
The flow dividing valve divides the flow rate from port 0 equally to port 3 and port 4. This is achieved using two measuring orifices R1 and R2, each with the same constant resistance and two variable control resistors. The control resistors are unified in a pressure compensator.    The pressures p1 and p2 are compared with the pressure compensator. By unequal pressures, the control slide valve extends and changes the cross-section area of the leading edges, which leads to a flow rate increase or decrease over the leading edge resp. The effects of flow forces and the forces of inertia are ignored by the flow dividing valve in FluidSIM. The control slide valve proceeds so long until the adjacent forces are balanced and p1 = p2 is valid.    The pressure differences at the measuring orifices R1 und R2 are therefore equal (p0 - p1 = p0 - p2). As both measuring orifices have the same resistance, then their volumetric flow is also equal.    A hydraulic resistance can be defined in FluidSIM. This refers to the individual measuring orifices and the completely opened leading edges respectively.  
Model of the flow dividing valve
Simulating with FluidSIM
Tutorial

p1_3_11.ct
Tutorial < Mathematical models < Model of the piloted pressure relief valve
Model of the piloted pressure relief valve
Mathematical models
The valve is closed in the idle position. The hydraulic fluid drains off at T, when the pressure difference at the ports P and T exceeds the nominal pressure. If the pressure falls below the preset value, the valve closes again.     The piloted pressure relief valve consists of a pilot stage, a main stage and an orifice (R). When open, there is less volumetric flow at the pilot stage that leads to port Y.    When closed, there is no volumetric flow at the orifice R. The pressures pP and pD, adjacent to the  pressure compensator of the main stage, are equal, and the main stage remains closed due to the low spring force. The pilot stage opens as soon as its' preset opening pressure is exceeded. A lower volumetric flow drains off at the leading edge of the pilot stage. This leads to a fall in pressure at the orifice R. pP is now larger than pD, and the main stage opens as soon as the spring force is overcome.  The piloted pressure relief valve is especially suitable for larger flow rates, as the pressure increase of pP is only dependent upon the low volumetric flow of the pilot stage.    Two parameters can be defined in FluidSIM:    ·	nominal pressure (inlet pressure) of the pilot stage  ·	hydraulic resistance of the fully opened main stage    In FluidSIM the main stage opens at a pressure of 0.05 MPa (0.5 bar), the hydraulic resistance of the orifice R is 1 MPa/(l/min)2 and the hydraulic resistance of the fully opened pilot stage 0.01 MPa/(l/min)2.    
Model of the piloted pressure relief valve
Simulating with FluidSIM
Tutorial

p1_3_12.ct
Tutorial < Mathematical models < Model of the piloted pressure regulating valve
Model of the piloted pressure regulating valve
Mathematical models
The piloted pressure regulating valve consists of a pilot stage, a main stage and an orifice (R).  If the pilot stage is closed, then there is no volumetric flow at the orifice R. The pressures pA und pD, adjacent to the pressure compensator of the main stage, are equal and the main stage remains closed due to the low spring force. The pilot stage opens as soon as its' preset opening pressure is exceeded. A lower volumetric flow drains off at the leading edge of the pilot stage. This leads to a fall in pressure at the orifice R. pA is now larger than pD, and the main stage begins to close as soon as the spring force is overcome.    The piloted pressure regulating valve is especially suitable for larger flow rates, as the pressure increase of pA is only dependent upon the low volumetric flow of the pilot stage.    Two parameters can be defined in FluidSIM:    ·	nominal pressure (inlet pressure) of the pilot stage  ·	hydraulic resistance of the fully opened main stage    In FluidSIM the main stage closes at a pressure of 0.05 MPa (0.5 bar), the hydraulic resistance of the orifice R is 1 MPa/(l/min)2 and the hydraulic resistance of the fully opened pilot stage 0.01 MPa/(l/min)2.    
Model of the piloted pressure regulating valve
Simulating with FluidSIM
Tutorial

p1_3_13.ct
Tutorial < Mathematical models < Model of the cylinder
Model of the cylinder
Mathematical models
FluidSIM makes use of a complex cylinder model. The model includes the following effects:    ·	moment of inertia of the moving mass  ·	mounting angle, which affects the force of gravity on the moving mass   ·	friction  	It is the static friction, Newton's and Coulomb's sliding friction of the cylinder piston and a modeled external mass, that make it possible to simulate the Stick-Slip- effect.  ·	by cylinders with a return spring; a spring force proportional to the spring constant  ·	a user defined force profile  ·	the internal leakage caused by leaking gaskets  ·	a simplified model for the buffer stop  ·	the piston distance dependent volumes in the cylinder chamber during the pressure build-up    
Model of the cylinder
Simulating with FluidSIM
Tutorial

p1_3_13_1.ct
Tutorial < Mathematical models < Model of the cylinder < Equilibrium of forces
Model of the cylinder
Mathematical models
The following equation defines the equilibrium of forces within the cylinder. As the atmospheric pressure remains the same for the complete cylinder, the pressures are specified as excess pressures p1_2_1_1.  
Equilibrium of forces
with    p1 excess pressure at connection 1,     p2 excess pressure at connection 2,     A1 effective piston area at the side of connection 1,     A2 effective piston area (piston-ring area) at the side of connection 2,     m moving cylinder mass,     a acceleration of the moving cylinder mass     FF friction depending on velocity p1_3_13_1_1     FW the counteracting force of gravity during the extension p1_3_13_1_2     FE the user defined force p1_3_13_1_3     FS the spring force of cylinders with spring return p1_3_13_1_4    Through the model of the equilibrium of forces in the cylinder, it is possible to observe a number of physical phenomenons:    ·	frictional force of a moving mass p1_1_1  ·	moment of inertia p1_1_3  ·	difference between theoretical and effective piston force p1_2_2  ·	stick-slip effect  
Equilibrium of forces
Simulating with FluidSIM
Tutorial

p1_3_13_1_1.ct
Tutorial < Mathematical models < Model of the cylinder < Equilibrium of forces < Friction depending on velocity
Mathematical models
It is composed of static friction, Newton's and Coulomb's sliding friction of the cylinder piston, and the static friction and Coulomb's sliding friction of the external mass.  Considering how complex the piston friction is (and it is different for every cylinder), the parameters for the piston force can only be defined exactly through taking measurements. The parameters in FluidSIM are therefore empirical values. The following diagram shows the typical course of the speed dependent cylinder friction (Stribeck-curve).    The following characteristics for the friction of the external mass can be defined in FluidSIM by the user:     µB coefficient of static friction (e.g. 0.15 for steel on steel)   µC coefficient of sliding friction (e.g. 0.1 for steel on steel)   mm the mass to be moved   a mounting angle of cylinder (e.g. 0° horizontal, 90° vertical movement)  The following frictional forces for external masses result under gravitational acceleration g ˜ 9.81 m/s²:    static friction: FB = µB · mm · g · cos(a)    sliding friction: FC = µC · mm · g · cos(a)  
Equilibrium of forces
Friction depending on velocity
A detailed example regarding the movement of an external mass can be found in the experiment: moving a mass p1_1_1.  
Friction depending on velocity
The coefficient of friction can be set in the properties dialog of the cylinder under "external load".
Simulating with FluidSIM
Model of the cylinder
Tutorial

p1_3_13_1_2.ct
Tutorial < Mathematical models < Model of the cylinder < Equilibrium of forces < The counteracting force of gravity during the extension
Mathematical models
FW = m · g · sin(a)    with    m moving cylinder mass    g ˜ 9.81 m/s² gravitational acceleration     a mounting angle of the cylinder (e.g. 0° horizontal, 90° vertical)    
The counteracting force of gravity during the extension
The counteracting force of gravity during the extension
The installation angle of the cylinder can be set in the property dialog of the cylinder under "Parameters".    Please note that, the rotation of the component symbols has no effect on the installation angle as used in the simulation.    The moving mass can be set in the property dialog of the cylinder under "external load".  
Simulating with FluidSIM
Model of the cylinder
Equilibrium of forces
Tutorial

p1_3_13_1_3.ct
Tutorial < Mathematical models < Model of the cylinder < Equilibrium of forces < The user-specified force
Mathematical models
A user defined force can additionally counteract the extension. It can be set, as a constant or a variable force during the piston position, in the properties dialog (double click to open) of the cylinder.
The user-specified force
The user-specified force
A constant force or a force profile can be defined in the properties dialog of the cylinder.  
User-specified force profile  
Simulating with FluidSIM
Model of the cylinder
Equilibrium of forces
Tutorial

p1_3_13_1_4.ct
Tutorial < Mathematical models < Model of the cylinder < Equilibrium of forces < The spring force of cylinders with spring return
Mathematical models
The parameters for spring constants and pre-tensioning force are calculated empirically by FluidSIM.
The spring force of cylinders with spring return
The spring force of cylinders with spring return
The spring return for single acting cylinders can be set under „configuration"  in the properties dialog (double click to open) of the cylinder.  
Simulating with FluidSIM
Model of the cylinder
Equilibrium of forces
Tutorial

p1_3_13_2.ct
Tutorial < Mathematical models < Model of the cylinder < Leakage
Mathematical models
Leaking gaskets can be simulated in FluidSIM. For this purpose, an internal leak unequal to zero can be specified. The leakage flow rate qL from connection 1 to 2 is assumed to be a laminar flow p1_2_1_4_3 and is calculated as follows:  
Leakage
with  qL leakage flow [m3/s]  k conductance [m3/(s×Pa)]    The acceleration a is calculated from the equilibrium of forces. In time, this can be used to calculate the speed and the distance covered with the following differential equation:    
From the piston speed and the adjacent pressures, volumetric flow rate in, and out of the cylinder chambers can be calculated. The following equations therefore apply to the volumetric flow in the connections 1 and 2:  
The pressure build-up in the cylinder chambers during this period is described under pressure build-up in a volume p1_2_1_8_1. At the same time, the volumes are calculated corresponding to the piston position.  
Leakage
Simulating with FluidSIM
Model of the cylinder
Tutorial

p1_3_14.ct
Tutorial < Mathematical models < Model of the rotary drive
Model of the rotary drive
Mathematical models
The motor and the semi-rotary actuator both occupy the same model, whereby the semi-rotary actuator has a swivel range with limit stop. The following parameters are considered:    ·	displacement V [m3]  ·	friction f [Nm×s/rad] with rad as radian  ·	moment of inertia I [kg×m2]  ·	external torque Mext [Nm]  ·	internal leakage k [m3/(s×Pa)]  
Model of the rotary drive
Simulating with FluidSIM
Tutorial

p1_3_14_1.ct
Tutorial < Mathematical models < Model of the rotary drive < Equilibrium of torque
Model of the rotary drive
Mathematical models
The following equation defines the equilibrium of torque in the rotary drive:  
Equilibrium of torque
with    MPV: pressure- and swept volume dependent torque  Mext: external torque  n: angular velocity in rad/s  a: angular acceleration in rad/s²      The pressure- and swept volume dependent torque MPV is given through:    
Equilibrium of torque
Simulating with FluidSIM
Tutorial

p1_3_14_2.ct
Tutorial < Mathematical models < Model of the rotary drive < Leakage
Mathematical models
Leaking gaskets can be simulated in FluidSIM. For this purpose, an internal leak unequal to zero can be specified. The leakage flow rate qL from connection 1 to 2 is assumed to be a laminar flow p1_2_1_4_3 and is calculated as follows:  
Leakage
with  qL leakage flow [m3/s]  k conductance [m3/(s×Pa)]    
Leakage
Simulating with FluidSIM
Model of the rotary drive
Tutorial

p1_3_14_3.ct
Tutorial < Mathematical models < Model of the rotary drive < Angular velocity
Mathematical models
The angular velocity a is calculated from the equilibrium of torque. In time, this can be used to calculate the angular velocity v with the following differential equation:  
Angular velocity
The mass flow rate from connection 1 to connection 2 is calculated with the following equation:  
Angular velocity
Simulating with FluidSIM
Model of the rotary drive
Tutorial

p1_3_15.ct
Tutorial < Mathematical models < Simulation methods
All models in FluidSIM have been created using the modeling language Modelicaã [7] p1_4_2. Modelica is a freely available, object-oriented modeling language for large, complex and heterogeneous technical systems. Models of different domains can be described using Modelica e.g. mechanics, electrical engineering, hydraulics and pneumatics. Models are mathematically described in Modelica using differential, algebraic and discrete equations. More information can be found at www.Modelica.org. A separate Modelica-library was especially developed for FluidSIM which does not use any models contained in the Modelica standard library.    A new, highly efficient, state-of-the-art Modelica simulator was developed for FluidSIM, for the calculation of the models described with Modelica. The simulator falls back on a number of symbolic and numerical methods for the solution of linear, non-linear and differential-algebraic equations.    Various integration algorithms are available to the simulator that can be intelligently selected and controlled at runtime. Integration algorithms implemented amongst others are:   ·	explicit single-step method, e.g. Dormand-Prince [5] p1_4_2  ·	implicit single-step method, e.g. Radau5 [6] p1_4_2  ·	explicit multiple-step method, e.g. Adams [5] p1_4_2  ·	implicit multiple-step method, e.g. Gear [5, 6] p1_4_2    All algorithms are equipped with an incremental control and facilitate the selection of any interpolated interim values. (Dense-Output).    
Simulation methods
Simulating with FluidSIM
Tutorial
Simulation methods
Mathematical models

p1_3_2.ct
Tutorial < Mathematical models < Model of the pump
Model of the pump
Mathematical models
The pump model takes four parameters into account:    ·	revolution  ·	displacement   ·	maximum pressure  ·	internal leakage    The pump delivers a volumetric flow that results from the product of revolutions and displacement volume. The volumetric flow remains constant as long as the maximum pressure has not been reached. The pump can only deliver the specified volumetric flow when sufficient hydraulic fluid returns via the suction connection.     The pressure results from the resistance of the attached components. Close to the maximum pressure, the delivery flow rate drops until, at the specified pressure, it reaches exactly zero. In practice, exceeding the maximum pressure can lead to pump damage. FluidSIM does not take this into account.    If an internal leakage greater than zero is specified, then the delivery rate is reduced by the leakage flow (rate). The leakage flow is modeled as a laminar flow p1_2_1_4_3.  
Model of the pump
Simulating with FluidSIM
Tutorial

p1_3_3.ct
Tutorial < Mathematical models < Model of the hydraulic reservoir
Model of the hydraulic reservoir
Mathematical models
The construction of a hydraulic reservoir consists of a pressure resistant container, a gas charge of nitrogen and a separator, e.g. a piston or an elastomer.    Internally the reservoir in FluidSIM is composed of two components: the actual reservoir in which the pressure build-up takes place and a laminar throttle p1_2_1_4_3 with low resistance, through which the hydraulic fluid flows into the reservoir.    Two parameters can be specified in FluidSIM:    ·	volume V0  ·	gas-preload pressure p0    The following equation is used - in the reservoir - to calculate the absolute pressure p1:  
Model of the hydraulic reservoir
Simulating with FluidSIM
Tutorial
with    	p0	 = absolute gas-preload pressure [Pa]  	V0	 = gas volume at p0 [m3]  	p1	 = absolute pressure [Pa]  	V1	 = gas volume at p1 [m3]  	n	 = exponent    For n = 1 an isothermal transformation of state is assumed. The change in pressure is executed so slowly that a complete heat exchange with the environment takes place.    For n = 1.4 an adiabatic transformation of state is assumed. The change in pressure is executed so quickly that no heat exchange with the environment takes place. FluidSIM calculates with n = 1.4.    The gas volume V1 results from the difference between the gas volume V0 and the flowed volume of hydraulic fluid.  

p1_3_4.ct
Tutorial < Mathematical models < Flow rate model of components with a constant cross-section
Flow rate model of components with a constant cross-section
Mathematical models
The flow rate is calculated using the flow rate model for turbulent flow p1_2_1_4_4. The hydraulic resistance can be specified either direct or graphically for these components.    Adjustable flow control valves and orifices are also classed as components with a constant cross-section, as the cross-section can only be changed manually and is not pressure dependent.    The hydraulic resistance is converted internally to the hydraulic conductance for the simulation. The conductance k behaves proportionally to the pre-set opening level with these components L. If kmax is the conductance resulting from the specified hydraulic resistance (opening level 100%), then k is calculated as follows:    
Flow rate model of components with a constant cross-section
Simulating with FluidSIM
Tutorial

p1_3_5.ct
Tutorial < Mathematical models < Model of the hydraulic line
Model of the hydraulic line
Mathematical models
Two hydraulic ports are connected in FluidSIM using a hydraulic line. This can be a simple connection or a T-junction. The simulation does not take pressure loss into account by this type of connection - the pressure is equal at all combined ports.    Should a pressure loss in the system be simulated, then the component "hose" can be used, which is modeled with a flow rate model with a constant cross-section p1_3_4. The volume of the hydraulic line and the mass of the hydraulic fluid are disregarded.      
Model of the hydraulic line
Simulating with FluidSIM
Tutorial

p1_3_6.ct
Tutorial < Mathematical models < Flow rate model of components with pressure dependent cross-section
Flow rate model of components with pressure dependent cross-section
Mathematical models
The following items, amongst others, belong to the class of components with pressure dependent cross-section: non-return valves, pressure control valves and pressure compensators.    The flow rate is calculated using the flow rate model for turbulent flow p1_2_1_4_4. The resistance is not constant by these components, instead it dependent upon the pressure ratios. The hydraulic resistance for these components can be specified at the maximum opening, which is internally converted to the maximum conductance kmax.    The flow is released against a spring (e.g. non-return valves) or blocked (e.g. pressure control valves). The adjustable nominal pressure is internally converted to a spring preload. The distance covered towards the spring, is proportional to the acting forces that are defined by the acting pressures and effective areas.  The actual conductance k is proportional to the distance covered.    The effects of friction and mass of the moving components are not considered in FluidSIM.  
Flow rate model of components with pressure dependent cross-section
Simulating with FluidSIM
Tutorial

p1_3_7.ct
Tutorial < Mathematical models < Model of the configurable way valve
Model of the configurable way valve
Mathematical models
The flow rate through a way valve is modeled similar to a component with constant cross-section p1_3_4.  The hydraulic resistance always relates to one leading edge.    A complex model was created for the switching characteristics, which takes the adjacent forces, area ratios, pilot control and switching times into account.    The switching times cannot be changed by the user. In FluidSIM the following realistic switching times have been permanently set:    ·	20 ms to activate the valve  ·	30 ms for the valve to return through spring tension    Whether or not a way valve switches, depends on the balance of the adjacent forces that can arise from a solenoid valve, a mechanical or a hydraulic activation. At the main stage, a force of at least 20 N and for the pilot stage at least 15 N is necessary. The way valve can always be overridden by the user. The spring return is only active when the switching force exceeds 20 N.    The following activation forces are set permanently in FluidSIM:    ·	25 N by an electrical activation  ·	30 N by a mechanical activation  ·	F = p · A (with A = 1 cm2) by a hydraulic activation with a normal and dominating signal respectively  ·	F = p · A (with A = 0.5 cm2) by a hydraulic activation with a non-dominating signal    If you have configured a way valve with a pilot control, then the activation forces refer to the pilot stage, which switches by 15 N. The hydraulic fluid, which switches the main stage via the pilot stage, can be applied internally or externally. For an external supply, a separate port is available. For an internal supply, the hydraulic fluid is tapped from a main stage port. This is port P by the 2/n-, 3/n and 4/n way valves, by all others it is port A.  
Model of the configurable way valve
Simulating with FluidSIM
Tutorial

p1_3_8.ct
Tutorial < Mathematical models < Model of the 2-way flow control valve
Model of the 2-way flow control valve
Mathematical models
The flow control valve holds the volumetric flow constant, independent of the adjacent pressure difference and the temperature of the hydraulic fluid. This is achieved using a measuring orifice which holds the pressure difference to a large extent constant. As the measuring orifice has a constant (adjustable) resistance, the volumetric flow also remains largely constant (see resistance of orifices p1_2_1_4_4_1).    As can be seen in the illustration, FluidSIM models the flow control valve with an upstream (closing) pressure compensator. Should a downstream pressure compensator be used, then these components can be recreated using a pressure compensator and an orifice.    The following applies to the equilibrium of forces at the pressure compensator by neglection of the flow-, inertia- and friction forces:  
Model of the 2-way flow control valve 
Simulating with FluidSIM
Tutorial
with    	p2	 = pressure in front of the measuring orifice  	p3	 = pressure behind the measuring orifice  	A	 = piston area of the valve slide of the pressure compensator  	FS	 = spring force of the pressure compensator    The spring force FS is essentially the spring pre-tensioning force and remains largely constant, as the valve slider only covers a short distance. The pressure difference p2 - p3 above the measuring orifice is therefore kept constant and the resulting volumetric flow remains constant and is only dependent upon the resistance of the measuring orifice. This is, however, only true when the pressure difference p2 - p3 reaches at least the spring force. The minimum pressure difference in FluidSIM is 0.1 MPa (1 bar).    Two parameters can be defined in FluidSIM:    ·	nominal flow rate q0  ·	hydraulic resistance RH of the fully opened pressure compensator    By specifying the nominal flow rate q0, the user does not need to calculate the resistance of the measuring orifice manually. The following flow rate equation is valid for a measuring orifice with a minimum pressure difference of 0.1 MPa:  

p1_3_9.ct
Tutorial < Mathematical models < Model of the 3-way flow control valve
Model of the 3-way flow control valve
Mathematical models
The flow control valve holds the volumetric flow constant, independent of the adjacent pressure difference and the temperature of the hydraulic fluid. This is achieved using a measuring orifice which holds the pressure difference to a large extent constant. As the measuring orifice has a constant (adjustable) resistance, the volumetric flow also remains largely constant (see resistance of orifices p1_2_1_4_4_1).    The surplus hydraulic fluid is drained using an (opening) pressure compensator. The inlet pressure p1 is load dependent, i.e it changes with the outlet pressure p2. Therefore a parallel circuit of several 3-way flow control valves is not possible. In this case, the inlet pressures would be defined by the valve with the lowest inlet pressure. Compared to the 2-way flow control valve, the 3-way flow control valve is admittedly  more efficient in its' energy consumption.     The following applies to the equilibrium of forces at the pressure compensator by neglection of the flow-, inertia- and friction forces:
Model of the 3-way flow control valve
Simulating with FluidSIM
Tutorial
with    	p2	 = pressure in front of the measuring orifice  	p3	 = pressure behind the measuring orifice  	A	 = piston area of the valve slide of the pressure compensator  	FS	 = spring force of the pressure compensator    The spring force FS is essentially the spring pre-tensioning force and remains largely constant, as the valve slider only covers a short distance. The pressure difference p1 - p2 above the measuring orifice is therefore kept constant and the resulting volumetric flow remains constant and is only dependent upon the resistance of the measuring orifice. This is, however, only true when the pressure difference p1 - p2 reaches at least the spring force. The minimum pressure difference in FluidSIM is 0.1 MPa (1 bar).    Two parameters can be defined in FluidSIM:    ·	nominal flow rate q0  ·	hydraulic resistance RH of the fully opened pressure compensator    By specifying the nominal flow rate q0, the user does not need to calculate the resistance of the measuring orifice manually. The following flow rate equation is valid for a measuring orifice with a minimum pressure difference of 0.1 MPa:

p1_4.ct
Tutorial < Various
Various
Various
International System of Units (SI)
Here are the tables and references mentioned in the tutorial.  
Literature
Simulating with FluidSIM
Tutorial

p1_4_1.ct
Tutorial < Various < International System of Units (SI)
International System of Units (SI)
Various
International System of Units (SI)
SI base units    Base quantity	Equation-	Unit	Symbol	Conversions  	symbol   length	l	meter	m	decimeter: 1 dm = 0.1 m  				centimeter: 1 cm = 0.01 m  				millimeter: 1 mm = 0.001 m  mass	m	kilogram	kg	Gram: 1 g = 0.001 kg  time	t	second	s	minute: 1 min = 60 s  temperature	T	kelvin	K	0 °C = 273.15 K    Derived units    Base quantity	Equation-	Unit	Symbol	Conversions  	symbol     speed, velocity	v	meter per second	m/s  acceleration	a	meter per second	m/s2  		squared  force	F	Newton	N	1 N = 1 kg×m/s2  				kilonewton: 1 kN = 1000 N  area	A	square meter	m2  volume	V	cubic meter	m3	liter: 1 l = 1 dm3 = 0.001 m3  volumetric flow rate	q	cubic meter per	m3/s	1 l/s = 0.001 m3/s  		second  pressure	p	pascal	Pa	1 Pa = 1 N/m2  				kilopascal: 1 kPa = 1000 Pa  				megapascal: 1 MPa = 1000 kPa  				1 bar = 100 kPa = 105 Pa = 0.1 MPa  
Simulating with FluidSIM
Tutorial

p1_4_2.ct
Tutorial < Various < Literature
Literature
Various
Literature
[1] 	Beater P.: Entwurf hydraulischer Maschinen (1999)    [2] 	DIN 1343: Referenzzustand, Normzustand, Normvolumen; Begriffe und Werte (Ausgabe 1990-01)    [3] 	Festo Didactic: Textbook Hydraulics, Basic level (2004)    [4] 	Festo Didactic: Textbook Proportional hydraulics, Basic level (2004)    [5] 	Hairer E., Norsett S.P., Wanner G.: Solving Ordinary Differential Equations I. Nonstiff Problems (Second Edition 2000)    [6] 	Hairer E., Wanner G.: Solving Ordinary Differential Equations II. Stiff and Differential-Algebraic Problems (Second Edition 2002)    [7] 	Modelica Association:  Language definition and tutorial. www.modelica.org (2005)    [8] 	Murrenhoff H.: Grundlagen der Fluidtechnik, Teil 1: Hydraulik (2005)        
Simulating with FluidSIM
Tutorial

p2.ct
Component Library
Component Library
Electrical Components
Component Library
Electrical Components (American Standard)
Digital Components
GRAFCET Elements
Hydraulic Components
Component Library
Miscellaneous

p2_1.ct
Component library < Hydraulic Components
Component library
Hydraulic Components
Component library
Hydraulic Components
Service Components
Configurable Way Valves
Mechanically Actuated Directional Valves
Solenoid-actuated Directional Valves
Shutoff Valves
Pressure Control Valves
Pressure Switches
Flow Control Valves
Continuous valves
Actuators
Measuring Devices

p2_1_1.ct
Component library < Hydraulic Components < Service Components
Component library
Component library
Hydraulic Components
Service Components
Service Components
Pump unit
Pump unit (simplified)
Fixed displacement pump
Variable displacement pump
Proportional pump
Tank
Hose with quick-action coupling
Hydraulic reservoir
Hydraulic reservoir
Diaphragm accumulator with shutoff block
Filter
Cooler
Heater
Connection (hydraulic)
Line (hydraulic)
T-junction (hydraulic)

p2_1_10.ct
Component library < Hydraulic Components < Actuators
Component library
Component library
Hydraulic Components
Actuators
Actuators
Configurable cylinder
Double acting cylinder
Double acting cylinder with shock adsorber at stroke end
Double acting cylinder with in and out piston rod and shock adsorber at stroke end
Single acting cylinder
Hydraulic motor
Semi-rotary actuator

p2_1_10_1.ct
Component library < Hydraulic Components < Actuators < Configurable cylinder
Component library
Actuators
The configurable cylinder can be customized via its properties dialog 813. Almost any combination of piston type (single-acting, double-acting), the specification of the piston rods (double ended, with magnetic coupling or slide) and the number (none, one, two) is possible. An end position cushioning (without, with, adjustable) can also be defined. FluidSIM automatically adjusts the symbol according to the preset configuration.  In addition, a load to be moved (including possible static and sliding friction) and a variable force profile can be defined in the properties dialog 813.  In the component library from FluidSIM there are several pre-configured cylinders that can be inserted in your circuit and directly used. Should no suitable symbol be available, then simply choose the component with the most similarity to the required component, open the properties dialog 813 and adjust the configuration accordingly.  Adjustable parameters  	Max. stroke:	1 ... 5000 mm	(200)  	Piston position:	0 ... Max. stroke mm	(0)  	Piston diameter:	1 ... 1000 mm	(16)  	Piston rod diameter:	0 ... 1000 mm	(10)  	Mounting angle:	0 ... 360 Deg	(0)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  	Moving mass:	0 ... 10000 kg	(0)  	Static friction coefficient:	0 ... 2 	(0)  	Sliding friction coefficient:	0 ... 2 	(0)  	Force:	-1000000 ... 1000000 N	(0)  
Related Topics  Double acting cylinder p2_1_10_2   Double acting cylinder with shock adsorber at stroke end p2_1_10_3   Double acting cylinder with in and out piston rod and shock adsorber at stroke end p2_1_10_4   Single acting cylinder p2_1_10_5   Displacement encoder p2_2_3_3   [151]  Single acting cylinder p3_1_11_1   [152]  Plunger cylinder p3_1_11_2   [153]  Double acting cylinder p3_1_11_3   [154]  Double acting cylinder with end position cushioning p3_1_11_4   
Configurable cylinder
Configurable cylinder
Component library
Hydraulic Components

p2_1_10_2.ct
Component library < Hydraulic Components < Actuators < Double acting cylinder
Component library
Actuators
Double acting cylinder with piston rod on one side. The piston of the cylinder contains a permanent solenoid which can be used to operate a proximity switch.  Adjustable parameters  	Max. stroke:	1 ... 5000 mm	(200)  	Piston position:	0 ... Max. stroke mm	(0)  	Piston diameter:	1 ... 1000 mm	(16)  	Piston rod diameter:	0 ... 1000 mm	(10)  	Mounting angle:	0 ... 360 Deg	(0)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  	Moving mass:	0 ... 10000 kg	(0)  	Static friction coefficient:	0 ... 2 	(0)  	Sliding friction coefficient:	0 ... 2 	(0)  	Force:	-1000000 ... 1000000 N	(0)  
Related Topics  Double acting cylinder with shock adsorber at stroke end p2_1_10_3   Double acting cylinder with in and out piston rod and shock adsorber at stroke end p2_1_10_4   Single acting cylinder p2_1_10_5   Distance rule p2_6_1_7   [153]  Double acting cylinder p3_1_11_3   
Double acting cylinder
Double acting cylinder
Component library
Hydraulic Components

p2_1_10_3.ct
Component library < Hydraulic Components < Actuators < Double acting cylinder with shock adsorber at stroke end
Component library
Actuators
The piston of the cylinder is controlled by the connected pressure loads. The shock adsorber can be adjusted by means of two adjustment screws. The piston contains a permanent solenoid which can be used to operate a proximity switch.  Adjustable parameters  	Max. stroke:	1 ... 5000 mm	(200)  	Piston position:	0 ... Max. stroke mm	(0)  	Piston diameter:	1 ... 1000 mm	(16)  	Piston rod diameter:	0 ... 1000 mm	(10)  	Mounting angle:	0 ... 360 Deg	(0)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  	Moving mass:	0 ... 10000 kg	(0)  	Static friction coefficient:	0 ... 2 	(0)  	Sliding friction coefficient:	0 ... 2 	(0)  	Force:	-1000000 ... 1000000 N	(0)  
Related Topics  Double acting cylinder p2_1_10_2   Double acting cylinder with in and out piston rod and shock adsorber at stroke end p2_1_10_4   Single acting cylinder p2_1_10_5   Distance rule p2_6_1_7   [154]  Double acting cylinder with end position cushioning p3_1_11_4   
Double acting cylinder with shock adsorber at stroke end
Double acting cylinder with shock adsorber at stroke end
Component library
Hydraulic Components

p2_1_10_4.ct
Component library < Hydraulic Components < Actuators < Double acting cylinder with in and out piston rod and shock adsorber at stroke end
Component library
Actuators
The piston of the cylinder is controlled by the connected pressure loads. The shock adsorber can be adjusted by means of two adjustment screws. The piston of the cylinder contains a permanent solenoid which can be used to operate a proximity switch.  Adjustable parameters  	Max. stroke:	1 ... 5000 mm	(200)  	Piston position:	0 ... Max. stroke mm	(0)  	Piston diameter:	1 ... 1000 mm	(16)  	Piston rod diameter:	0 ... 1000 mm	(10)  	Mounting angle:	0 ... 360 Deg	(0)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  	Moving mass:	0 ... 10000 kg	(0)  	Static friction coefficient:	0 ... 2 	(0)  	Sliding friction coefficient:	0 ... 2 	(0)  	Force:	-1000000 ... 1000000 N	(0)  
Related Topics  Double acting cylinder p2_1_10_2   Double acting cylinder with shock adsorber at stroke end p2_1_10_3   Single acting cylinder p2_1_10_5   Distance rule p2_6_1_7   [154]  Double acting cylinder with end position cushioning p3_1_11_4   
Double acting cylinder with in and out piston rod and shock adsorber at stroke end
Double acting cylinder with in and out piston rod and shock adsorber at stroke end
Component library
Hydraulic Components

p2_1_10_5.ct
Component library < Hydraulic Components < Actuators < Single acting cylinder
Component library
Actuators
By connecting a sufficiently high pressure load, the piston of the cylinder is extended to its stop. To move the piston back, an external force must be applied.  Adjustable parameters  	Max. stroke:	1 ... 5000 mm	(200)  	Piston position:	0 ... Max. stroke mm	(0)  	Piston diameter:	1 ... 1000 mm	(16)  	Piston rod diameter:	0 ... 1000 mm	(10)  	Mounting angle:	0 ... 360 Deg	(0)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  	Moving mass:	0 ... 10000 kg	(0)  	Static friction coefficient:	0 ... 2 	(0)  	Sliding friction coefficient:	0 ... 2 	(0)  	Force:	-1000000 ... 1000000 N	(0)  
Related Topics  Double acting cylinder p2_1_10_2   Double acting cylinder with shock adsorber at stroke end p2_1_10_3   Double acting cylinder with in and out piston rod and shock adsorber at stroke end p2_1_10_4   Distance rule p2_6_1_7   [151]  Single acting cylinder p3_1_11_1   
Single acting cylinder
Single acting cylinder
Component library
Hydraulic Components

p2_1_10_6.ct
Component library < Hydraulic Components < Actuators < Hydraulic motor
Component library
Actuators
The hydraulic motor transforms hydraulic energy into mechanical energy.  Adjustable parameters  	Displacement:	0.001 ... 5 Liter	(0.0082)  	Friction:	0.01 ... 100 N*m*s/rad	(0.0128)  	Moment of inertia:	0.0001 ... 1 kg*m2	(0.0001)  	External torque:	-1000 ... 1000 Nm	(0)  
Related Topic  Semi-rotary actuator p2_1_10_7   
Hydraulic motor
Hydraulic motor
Component library
Hydraulic Components

p2_1_10_7.ct
Component library < Hydraulic Components < Actuators < Semi-rotary actuator
Component library
Actuators
The semi-rotary actuator is controlled by alternately switching the pressure.   In the end positions the swivel cylinder can activate switches or valves via labels.  Adjustable parameters  	Rotation angle:	1 ... 360 Deg	(180)  	Displacement:	0.001 ... 5 Liter	(0.1)  	Friction:	0.01 ... 100 N*m*s/rad	(0.1)  	Moment of inertia:	0.0001 ... 1 kg*m2	(0.001)  	External torque:	-1000 ... 1000 Nm	(0)  	Initial position:	Left, Right 	(Left)  
Related Topic  Hydraulic motor p2_1_10_6   
Semi-rotary actuator
Semi-rotary actuator
Component library
Hydraulic Components

p2_1_11.ct
Component library < Hydraulic Components < Measuring Devices
Component library
Component library
Hydraulic Components
Measuring Devices
Measuring Devices
Manometer
Differential pressure gauge
Pressure indicator
Pressure sensor, analog
Flow meter
Flow meter
Flow meter, analog

p2_1_11_1.ct
Component library < Hydraulic Components < Measuring Devices < Manometer
Component library
Measuring Devices
The manometer measures the pressure at its connection.  
Related Topics  Differential pressure gauge p2_1_11_2   Pressure indicator p2_1_11_3   Pressure sensor, analog p2_1_11_4   [160]  Piston pressure gauge p3_1_12_1   [161]  Bourdon-tube pressure gauge p3_1_12_2   
Manometer
Manometer
Component library
Hydraulic Components

p2_1_11_2.ct
Component library < Hydraulic Components < Measuring Devices < Differential pressure gauge
Component library
Measuring Devices
The differential pressure gauge displays the pressure difference between the adjacent pressures at the left and the right connection.  
Related Topic  Manometer p2_1_11_1   
Differential pressure gauge
Differential pressure gauge
Component library
Hydraulic Components

p2_1_11_3.ct
Component library < Hydraulic Components < Measuring Devices < Pressure indicator
Component library
Measuring Devices
An optical signal is activated when the pressure at the connection to the pressure display exceeds the preset switching pressure.  Adjustable parameters  	Switching pressure:	0.0001 ... 40 MPa	(3)  	Color:	16 standard colors 	(Dark red)  
Related Topic  Manometer p2_1_11_1   
Pressure indicator
Pressure indicator
Component library
Hydraulic Components

p2_1_11_4.ct
Component library < Hydraulic Components < Measuring Devices < Pressure sensor, analog
Component library
Measuring Devices
This symbol represents the hydraulic part of the analog pressure sensor. The analog pressure sensor measures the adjacent pressure and transforms it into a proportional electrical voltage signal. In the process, only pressures in the specified pressure ranges are considered. Within this range, the pressure in the voltage range from 0 V to 10 V is represented, i.e. the minimum pressure delivers 0 V and the maximum pressure 10 V.  
Related Topics  Manometer p2_1_11_1   Coupling Hydraulics, Electrics and Mechanics 49   Open-loop and Closed-loop Control by using Continuous Valves 814   
Pressure sensor, analog
Pressure sensor, analog
Component library
Hydraulic Components

p2_1_11_5.ct
Component library < Hydraulic Components < Measuring Devices < Flow meter
Component library
Measuring Devices
The flow meter measures the flow rate. Either the current flow or the total quantity flowed can be displayed. The component image is automatically adjusted accordingly.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.0001)  
Related Topics  Flow meter p2_1_11_6   Flow meter, analog p2_1_11_7   [162]  Flow meter p3_1_12_3   
Flow meter
Flow meter
Component library
Hydraulic Components

p2_1_11_6.ct
Component library < Hydraulic Components < Measuring Devices < Flow meter
Component library
Measuring Devices
The flow meter consists of a hydraulic motor connected to an RPM gauge.  Adjustable parameters  	Displacement:	0.001 ... 5 Liter	(0.0082)  	Friction:	0.01 ... 100 N*m*s/rad	(0.1)  	Moment of inertia:	0.0001 ... 1 kg*m2	(0.0001)  	External torque:	-1000 ... 1000 Nm	(0)  
Related Topics  Hydraulic motor p2_1_10_6   Flow meter p2_1_11_5   
Flow meter
Flow meter
Component library
Hydraulic Components

p2_1_11_7.ct
Component library < Hydraulic Components < Measuring Devices < Flow meter, analog
Component library
Measuring Devices
This symbol represents the hydraulic part of the analog flow meter. The analog flow meter measures the volumetric flow and transforms it into a proportional electrical voltage signal. In the process, only flow rates in the specified pressure ranges are considered. Within this range, the flow rate in the voltage range from 0 V to 10 V is represented, i.e. the minimum volumetric flow delivers 0 V and the maximum volumetric flow 10 V.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.0001)  
Related Topics  Flow meter p2_1_11_5   Flow meter, analog p2_2_3_5   
Flow meter, analog
Flow meter, analog
Component library
Hydraulic Components

p2_1_1_1.ct
Component library < Hydraulic Components < Service Components < Pump unit
Component library
Service Components
The pump unit supplies a constant volumetric flow. The operating pressure is limited by the internal pressure relief valve. The pump unit has two tank connections.  Adjustable parameters  	Max. pressure:	0.01 ... 40 MPa	(6)  	Flow:	0 ... 500 l/min	(2.4)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0.04)  
Related Topics  Pump unit (simplified) p2_1_1_2   [38]  Hydraulic power unit p3_1_5_1   [40]  Externally toothed gear pump p3_1_5_3   [41]  Internally toothed gear pump p3_1_5_4   
Pump unit
Pump unit
Component library
Hydraulic Components

p2_1_1_10.ct
Component library < Hydraulic Components < Service Components < Diaphragm accumulator with shutoff block
Component library
Service Components
Stores the pressure and is equipped with a pressure relief valve to prevent overpressure.   Adjustable parameters  	Nominal pressure:	0 ... 35 MPa	(6)  	Gas pre-charge pressure:	0.1 ... 35 MPa	(1)  
Related Topics  Hydraulic reservoir p2_1_1_8   Hydraulic reservoir p2_1_1_9   
Diaphragm accumulator with shutoff block
Diaphragm accumulator with shutoff block
Component library
Hydraulic Components

p2_1_1_11.ct
Component library < Hydraulic Components < Service Components < Filter
Component library
Service Components
The filter limits the contamination of the fluid respecting a certain tolerance value in order to reduce the risk of damage at the components.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.0001)  
Related Topics  Pump unit p2_1_1_1   [38]  Hydraulic power unit p3_1_5_1   [42]  Circuit diagram: Return flow filter p3_1_5_5   [43]  Circuit diagram : Pump inlet filter p3_1_5_6   [44]  Circuit diagram: Pressure line filter p3_1_5_7   [45]  Circuit diagram: Contamination indicator p3_1_5_8   
Filter
Filter
Component library
Hydraulic Components

p2_1_1_12.ct
Component library < Hydraulic Components < Service Components < Cooler
Component library
Service Components
An unacceptable fall in the hydraulic fluid's viscosity can be avoided through the use of a cooler.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.0001)  
Related Topics  Heater p2_1_1_13   [46]  Water cooler p3_1_5_9   [47]  Air cooler p3_1_5_10   
Cooler
Cooler
Component library
Hydraulic Components

p2_1_1_13.ct
Component library < Hydraulic Components < Service Components < Heater
Component library
Service Components
The hydraulic fluid's optimal viscosity can be reached quickly through the use of a heater.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.0001)  
Related Topics  Cooler p2_1_1_12   [48]  Heating element p3_1_5_11   
Heater
Heater
Component library
Hydraulic Components

p2_1_1_14.ct
Component library < Hydraulic Components < Service Components < Connection (hydraulic)
Component library
Service Components
A hydraulic connection is a place where a hydraulic line can be attached to. To simplify the line drawing process, a connection appears as a small circle in Edit Mode.   Hydraulic connections can be shut by means of a blind plug. An open hydraulic connection may result in leaking oil; FluidSIM-H thus pops up a warning message, if some hydraulic connection was left open.   Note that at each hydraulic connection values for the flow and pressure can be displayed.  
Related Topics  Line (hydraulic) p2_1_1_15   T-junction (hydraulic) p2_1_1_16   Creating new Circuit Diagrams 19   Insertion of T-connections 43   Setting Blind Plugs 34   Drawing Errors 452   Displaying Quantity Values 45   
Connection (hydraulic)
Connection (hydraulic)
Component library
Hydraulic Components

p2_1_1_15.ct
Component library < Hydraulic Components < Service Components < Line (hydraulic)
Component library
Service Components
A hydraulic line links two hydraulic connections. Note that a hydraulic connection may be a simple hydraulic connection p2_1_1_14 or a T-junction p2_1_1_16. A hydraulic line causes no pressure drop, i. e., it has no fluidic resistance.   From a drawing point of view, FluidSIM distinguishes between control lines and main lines. The former is represented by a dashed line, the latter is represented by a solid line and establishes the default case.  Adjustable parameters  	Line Type:	Main Line or Control Line 	(Main Line)  
Related Topics  Creating new Circuit Diagrams 19   Setting Line Type 33   
Line (hydraulic)
Line (hydraulic)
Component library
Hydraulic Components

p2_1_1_16.ct
Component library < Hydraulic Components < Service Components < T-junction (hydraulic)
Component library
Service Components
A T-junction joins up to four hydraulic lines p2_1_1_15, thus having a single pressure potential. Note that T-junctions are introduced automatically by FluidSIM when dropping the line drawing cursor onto another line in Edit Mode.  
Related Topics  Connection (hydraulic) p2_1_1_14   Creating new Circuit Diagrams 19   
T-junction (hydraulic)
T-junction (hydraulic)
Component library
Hydraulic Components

p2_1_1_2.ct
Component library < Hydraulic Components < Service Components < Pump unit (simplified)
Component library
Service Components
Simplified representation of the detailed pump unit. The component does not have tank connections in the circuit diagram.  Adjustable parameters  	Max. pressure:	0.01 ... 40 MPa	(6)  	Flow:	0 ... 500 l/min	(2)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  
Related Topics  Pump unit p2_1_1_1   [38]  Hydraulic power unit p3_1_5_1   [40]  Externally toothed gear pump p3_1_5_3   [41]  Internally toothed gear pump p3_1_5_4   
Pump unit (simplified)
Pump unit (simplified)
Component library
Hydraulic Components

p2_1_1_3.ct
Component library < Hydraulic Components < Service Components < Fixed displacement pump
Component library
Service Components
The fixed displacement pump delivers a constant volumetric flow rate dependent upon the revolutions and the displacement volume.  Adjustable parameters  	Revolution:	0 ... 3000 1/min	(1320)  	Displacement:	0.001 ... 1 Liter	(0.0016)  	Max. pressure:	0.1 ... 40 MPa	(6)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  
Related Topics  Variable displacement pump p2_1_1_4   [40]  Externally toothed gear pump p3_1_5_3   [41]  Internally toothed gear pump p3_1_5_4   
Fixed displacement pump
Fixed displacement pump
Component library
Hydraulic Components

p2_1_1_4.ct
Component library < Hydraulic Components < Service Components < Variable displacement pump
Component library
Service Components
The revolutions of the variable displacement pump can be changed under operating conditions. The pump delivers a variable volumetric flow rate dependent upon the variable revolutions and the displacement volume.  Adjustable parameters  	Revolution:	0 ... 3000 1/min	(1320)  	Displacement:	0.001 ... 1 Liter	(0.0016)  	Max. pressure:	0.1 ... 40 MPa	(6)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  
Related Topics  Fixed displacement pump p2_1_1_3   Proportional pump p2_1_1_5   [40]  Externally toothed gear pump p3_1_5_3   [41]  Internally toothed gear pump p3_1_5_4   
Variable displacement pump
Variable displacement pump
Component library
Hydraulic Components

p2_1_1_5.ct
Component library < Hydraulic Components < Service Components < Proportional pump
Component library
Service Components
The revolutions of the variable displacement pump can be changed proportionally from zero to maximum through a voltage signal between 0 V and 10 V and the assistance of a proportional-amplifier. The pump delivers a variable volumetric flow rate dependent upon the variable revolutions and the displacement volume.  Adjustable parameters  	Max. Revolution:	0 ... 3000 1/min	(1320)  	Displacement:	0.001 ... 1 Liter	(0.0016)  	Max. pressure:	0.1 ... 40 MPa	(6)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  
Related Topics  Proportional amplifier, 1-channel p2_6_1_4   Variable displacement pump p2_1_1_4   [40]  Externally toothed gear pump p3_1_5_3   [41]  Internally toothed gear pump p3_1_5_4   
Proportional pump
Proportional pump
Component library
Hydraulic Components

p2_1_1_6.ct
Component library < Hydraulic Components < Service Components < Tank
Component library
Service Components
The tank is integrated into the pump unit and has a pressure of 0 MPa. It can be inserted into the circuit diagram as an independent component.  
Related Topics  Pump unit p2_1_1_1   [39]  Hydraulic power unit: Reservoir p3_1_5_2   
Tank
Tank
Component library
Hydraulic Components

p2_1_1_7.ct
Component library < Hydraulic Components < Service Components < Hose with quick-action coupling
Component library
Service Components
The hose is available in 3 lengths: 600 mm, 1500 mm, and 3000 mm. The pressure loss in a hose is taken into account by specifying a hydraulic resistance. In FluidSIM no pressure loss is simulated with simple connections between two components.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.012)  
Hose with quick-action coupling
Hose with quick-action coupling
Component library
Hydraulic Components

p2_1_1_8.ct
Component library < Hydraulic Components < Service Components < Hydraulic reservoir
Component library
Service Components
The reservoir enables the performance of a hydraulic system to be optimized. For example, it can be utilized as an energy reservoir and for the absorbance of pressure surges or flow fluctuations. Reservoirs are capable of absorbing a defined volume of fluid under pressure and releasing it again with minimal losses. The construction consists essentially of a pressure resistant container, generally a gas charge of nitrogen and a separator e.g. a piston, a membrane or a bubble elastomer.   Hydraulic fluid only starts to flow into the reservoir when the fluid pressure is greater than the gas-preload pressure.  Adjustable parameters  	Volume:	0.01 ... 100 Liter	(0.32)  	Gas pre-charge pressure:	0 ... 40 MPa	(1)  
Related Topics  Hydraulic reservoir p2_1_1_9   Diaphragm accumulator with shutoff block p2_1_1_10   
Hydraulic reservoir
Hydraulic reservoir
Component library
Hydraulic Components

p2_1_1_9.ct
Component library < Hydraulic Components < Service Components < Hydraulic reservoir
Component library
Service Components
The reservoir enables the performance of a hydraulic system to be optimized. For example, it can be utilized as an energy reservoir and for the absorbance of pressure surges or flow fluctuations. Reservoirs are capable of absorbing a defined volume of fluid under pressure and releasing it again with minimal losses. The construction consists essentially of a pressure resistant container, generally a gas charge of nitrogen and a separator e.g. a piston, a membrane or a bubble elastomer.   Hydraulic fluid only starts to flow into the reservoir when the fluid pressure is greater than the gas-preload pressure.  Adjustable parameters  	Volume:	0.01 ... 100 Liter	(0.32)  	Gas pre-charge pressure:	0 ... 40 MPa	(1)  
Related Topics  Hydraulic reservoir p2_1_1_8   Diaphragm accumulator with shutoff block p2_1_1_10   
Hydraulic reservoir
Hydraulic reservoir
Component library
Hydraulic Components

p2_1_2.ct
Component library < Hydraulic Components < Configurable Way Valves
Component library
Component library
Hydraulic Components
Configurable Way Valves
Configurable Way Valves
Configurable 2/n way valve
Configurable 3/n way valve
Configurable 4/n way valve
Configurable 5/n way valve
Configurable 6/n way valve
Configurable 8/n way valve

p2_1_2_1.ct
Component library < Hydraulic Components < Configurable Way Valves < Configurable 2/n way valve
Component library
Configurable Way Valves
The configurable 2/n way valve is a way valve with two connections, where both its body elements 32 and its operation modes 32 are user-definable.   Additionally, the hydraulic connections can be closed with blind plugs 34.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  [17]  Circuit symbols for directional control valves (1) p3_1_3_7   [20]  Circuit symbols for manual operation p3_1_3_10   [21]  Circuit symbols for mechanical actuation p3_1_3_11   [88]  2/2-way valve (1) p3_1_8_1   [90]  2/2-way valve as by-pass valve p3_1_8_3   [92]  Circuit diagram: 2/2-way valve as final control element p3_1_8_5   
Configurable 2/n way valve
Configurable 2/n way valve
Component library
Hydraulic Components

p2_1_2_2.ct
Component library < Hydraulic Components < Configurable Way Valves < Configurable 3/n way valve
Component library
Configurable Way Valves
The configurable 3/n way valve is a way valve with three connections, where both its body elements 32 and its operation modes 32 are user-definable.   Additionally, the hydraulic connections can be closed with blind plugs 34.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  [17]  Circuit symbols for directional control valves (1) p3_1_3_7   [20]  Circuit symbols for manual operation p3_1_3_10   [21]  Circuit symbols for mechanical actuation p3_1_3_11   [55]  Negative switching overlap p3_1_6_6   [96]  3/2-way valve (poppet principle) (1) p3_1_8_9   [99]  Circuit diagram: 3/2-way valve as final control element p3_1_8_12   [101]  3/2-way valve (slide principle) (1) p3_1_8_14   [103]  3/2-way valves as diverter p3_1_8_16   
Configurable 3/n way valve
Configurable 3/n way valve
Component library
Hydraulic Components

p2_1_2_3.ct
Component library < Hydraulic Components < Configurable Way Valves < Configurable 4/n way valve
Component library
Configurable Way Valves
The configurable 4/n way valve is a way valve with four connections, where both its body elements 32 and its operation modes 32 are user-definable.   Additionally, the hydraulic connections can be closed with blind plugs 34.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  [18]  Circuit symbols for directional control valves (2) p3_1_3_8   [19]  Circuit symbols for directional control valves (3) p3_1_3_9   [20]  Circuit symbols for manual operation p3_1_3_10   [21]  Circuit symbols for mechanical actuation p3_1_3_11   [104]  4/2-way valve, two pistons (1) p3_1_8_17   [106]  4/2-way valve, three pistons (1) p3_1_8_19   [110]  4/3-way valve with pump bypass (1) p3_1_8_23   [116]  4/3-way valve with closed mid-position (1) p3_1_8_29   [121]  4/3-way valve: overlap positions (1) p3_1_8_34   
Configurable 4/n way valve
Configurable 4/n way valve
Component library
Hydraulic Components

p2_1_2_4.ct
Component library < Hydraulic Components < Configurable Way Valves < Configurable 5/n way valve
Component library
Configurable Way Valves
The configurable 5/n way valve is a way valve with five connections, where both its body elements 32 and its operation modes 32 are user-definable.   Additionally, the hydraulic connections can be closed with blind plugs 34.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  [20]  Circuit symbols for manual operation p3_1_3_10   [21]  Circuit symbols for mechanical actuation p3_1_3_11   
Configurable 5/n way valve
Configurable 5/n way valve
Component library
Hydraulic Components

p2_1_2_5.ct
Component library < Hydraulic Components < Configurable Way Valves < Configurable 6/n way valve
Component library
Configurable Way Valves
The configurable 6/n way valve is a way valve with six connections, where both its body elements 32 and its operation modes 32 are user-definable.   Additionally, the hydraulic connections can be closed with blind plugs 34.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Configurable 6/n way valve
Configurable 6/n way valve
Component library
Hydraulic Components

p2_1_2_6.ct
Component library < Hydraulic Components < Configurable Way Valves < Configurable 8/n way valve
Component library
Configurable Way Valves
The configurable 8/n way valve is a way valve with eight connections, where both its body elements 32 and its operation modes 32 are user-definable.   Additionally, the hydraulic connections can be closed with blind plugs 34.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Configurable 8/n way valve
Configurable 8/n way valve
Component library
Hydraulic Components

p2_1_3.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves
Component library
Component library
Hydraulic Components
Mechanically Actuated Directional Valves
Mechanically Actuated Directional Valves
2/2-way stem-Actuated valve (i)
2/2-way stem-Actuated valve (ii)
3/2-way hand-lever valve
4/2-way hand-lever valve (i)
4/2-way hand-lever valve (ii)
4/3-way hand-lever valve with shutoff position (i)
4/3-way hand-lever valve with shutoff position (ii)
4/3-way hand-lever valve with floating position (i)
4/3-way hand-lever valve with floating position (ii)
4/3-way hand-lever valve with bypass position (i)
4/3-way hand-lever valve with bypass position (ii)

p2_1_3_1.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 2/2-way stem-Actuated valve (i)
Component library
Mechanically Actuated Directional Valves
If the cylinder piston actuates the stem, flow is enabled from P to A.   This valve is derived from a configurable 2/n way valve p2_1_2_1. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 2/n way valve p2_1_2_1   2/2-way stem-Actuated valve (ii) p2_1_3_2   [21]  Circuit symbols for mechanical actuation p3_1_3_11   [88]  2/2-way valve (1) p3_1_8_1   
2/2-way stem-Actuated valve (i)
2/2-way stem-Actuated valve (i)
Component library
Hydraulic Components

p2_1_3_10.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/3-way hand-lever valve with bypass position (i)
Component library
Mechanically Actuated Directional Valves
In normal position the connections A and B are closed and P to T opened. When manually actuated the valve is set to parallel or crossover position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way hand-lever valve with bypass position (ii) p2_1_3_11   [110]  4/3-way valve with pump bypass (1) p3_1_8_23   
4/3-way hand-lever valve with bypass position (i)
4/3-way hand-lever valve with bypass position (i)
Component library
Hydraulic Components

p2_1_3_11.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/3-way hand-lever valve with bypass position (ii)
Component library
Mechanically Actuated Directional Valves
In normal position the connections A and B are closed and P to T opened. When manually actuated the valve is set to crossover or parallel position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way hand-lever valve with bypass position (i) p2_1_3_10   [110]  4/3-way valve with pump bypass (1) p3_1_8_23   
4/3-way hand-lever valve with bypass position (ii)
4/3-way hand-lever valve with bypass position (ii)
Component library
Hydraulic Components

p2_1_3_2.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 2/2-way stem-Actuated valve (ii)
Component library
Mechanically Actuated Directional Valves
If the cylinder piston actuate the stem, the flow from P to A is shut off.   This valve is derived from a configurable 2/n way valve p2_1_2_1. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 2/n way valve p2_1_2_1   2/2-way stem-Actuated valve (i) p2_1_3_1   [21]  Circuit symbols for mechanical actuation p3_1_3_11   [88]  2/2-way valve (1) p3_1_8_1   
2/2-way stem-Actuated valve (ii)
2/2-way stem-Actuated valve (ii)
Component library
Hydraulic Components

p2_1_3_3.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 3/2-way hand-lever valve
Component library
Mechanically Actuated Directional Valves
In normal position the connection P is closed and A to T opened. When manually actuated T is shut off and P to A opened.   This valve is derived from a configurable 3/n way valve p2_1_2_2. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 3/n way valve p2_1_2_2   [96]  3/2-way valve (poppet principle) (1) p3_1_8_9   
3/2-way hand-lever valve
3/2-way hand-lever valve
Component library
Hydraulic Components

p2_1_3_4.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/2-way hand-lever valve (i)
Component library
Mechanically Actuated Directional Valves
In normal position the connection P is open to B and A to T. When manually actuated the valve is set to parallel position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/2-way hand-lever valve (ii) p2_1_3_5   [104]  4/2-way valve, two pistons (1) p3_1_8_17   
4/2-way hand-lever valve (i)
4/2-way hand-lever valve (i)
Component library
Hydraulic Components

p2_1_3_5.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/2-way hand-lever valve (ii)
Component library
Mechanically Actuated Directional Valves
In normal position the connection P is open to A and B to T. When manually actuated the valve is set to crossover position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/2-way hand-lever valve (i) p2_1_3_4   [104]  4/2-way valve, two pistons (1) p3_1_8_17   
4/2-way hand-lever valve (ii)
4/2-way hand-lever valve (ii)
Component library
Hydraulic Components

p2_1_3_6.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/3-way hand-lever valve with shutoff position (i)
Component library
Mechanically Actuated Directional Valves
In normal position all connections are closed. When manually actuated the valve is set to parallel or crossover position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way hand-lever valve with shutoff position (ii) p2_1_3_7   [116]  4/3-way valve with closed mid-position (1) p3_1_8_29   
4/3-way hand-lever valve with shutoff position (i)
4/3-way hand-lever valve with shutoff position (i)
Component library
Hydraulic Components

p2_1_3_7.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/3-way hand-lever valve with shutoff position (ii)
Component library
Mechanically Actuated Directional Valves
In normal position all connections are closed. When manually actuated the valve is set to crossover or parallel position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way hand-lever valve with shutoff position (i) p2_1_3_6   [116]  4/3-way valve with closed mid-position (1) p3_1_8_29   
4/3-way hand-lever valve with shutoff position (ii)
4/3-way hand-lever valve with shutoff position (ii)
Component library
Hydraulic Components

p2_1_3_8.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/3-way hand-lever valve with floating position (i)
Component library
Mechanically Actuated Directional Valves
In normal position the connections A and B are open to T. When manually actuated the valve is set to parallel or crossover position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way hand-lever valve with floating position (ii) p2_1_3_9   
4/3-way hand-lever valve with floating position (i)
4/3-way hand-lever valve with floating position (i)
Component library
Hydraulic Components

p2_1_3_9.ct
Component library < Hydraulic Components < Mechanically Actuated Directional Valves < 4/3-way hand-lever valve with floating position (ii)
Component library
Mechanically Actuated Directional Valves
In normal position the connections A and B are open to T. When manually actuated the valve is set to crossover or parallel position.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way hand-lever valve with floating position (i) p2_1_3_8   
4/3-way hand-lever valve with floating position (ii)
4/3-way hand-lever valve with floating position (ii)
Component library
Hydraulic Components

p2_1_4.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves
Component library
Component library
Hydraulic Components
Solenoid-actuated Directional Valves
Solenoid-actuated Directional Valves
4/2-way solenoid valve (i)
4/2-way solenoid valve (ii)
4/3-way solenoid valve with shutoff position (i)
4/3-way solenoid valve with shutoff position (ii)
4/3-way solenoid valve with floating position (i)
4/3-way solenoid valve with floating position (ii)
4/3-way solenoid valve with bypass position (i)
4/3-way solenoid valve with bypass position (ii)

p2_1_4_1.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/2-way solenoid valve (i)
Component library
Solenoid-actuated Directional Valves
In normal position the connection P is open to B and A to T. When actuated by the control solenoid, the valve is set to parallel position. If no current is flowing through the control solenoid, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/2-way solenoid valve (ii) p2_1_4_2   [104]  4/2-way valve, two pistons (1) p3_1_8_17   
4/2-way solenoid valve (i)
4/2-way solenoid valve (i)
Component library
Hydraulic Components

p2_1_4_2.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/2-way solenoid valve (ii)
Component library
Solenoid-actuated Directional Valves
In normal position the connection P is open to A and B to T. When actuated by the control solenoid, the valve is set to crossover position. If no current is flowing through the control solenoid, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/2-way solenoid valve (i) p2_1_4_1   [104]  4/2-way valve, two pistons (1) p3_1_8_17   
4/2-way solenoid valve (ii)
4/2-way solenoid valve (ii)
Component library
Hydraulic Components

p2_1_4_3.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/3-way solenoid valve with shutoff position (i)
Component library
Solenoid-actuated Directional Valves
In normal position all connections are closed. When actuated by the control solenoids, the valve is set to parallel or crossover position. If no current is flowing through the control solenoids, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way solenoid valve with shutoff position (ii) p2_1_4_4   [116]  4/3-way valve with closed mid-position (1) p3_1_8_29   
4/3-way solenoid valve with shutoff position (i)
4/3-way solenoid valve with shutoff position (i)
Component library
Hydraulic Components

p2_1_4_4.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/3-way solenoid valve with shutoff position (ii)
Component library
Solenoid-actuated Directional Valves
In normal position all connections are closed. When actuated by the control solenoids, the valve is set to crossover or parallel position. If no current is flowing through the control solenoids, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way solenoid valve with shutoff position (i) p2_1_4_3   [116]  4/3-way valve with closed mid-position (1) p3_1_8_29   
4/3-way solenoid valve with shutoff position (ii)
4/3-way solenoid valve with shutoff position (ii)
Component library
Hydraulic Components

p2_1_4_5.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/3-way solenoid valve with floating position (i)
Component library
Solenoid-actuated Directional Valves
In normal position the connections A and B are open to T. When actuated by the control solenoids, the valve is set to parallel or crossover position. If no current is flowing through the control solenoids, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way solenoid valve with floating position (ii) p2_1_4_6   
4/3-way solenoid valve with floating position (i)
4/3-way solenoid valve with floating position (i)
Component library
Hydraulic Components

p2_1_4_6.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/3-way solenoid valve with floating position (ii)
Component library
Solenoid-actuated Directional Valves
In normal position the connections A and B are open to T. When actuated by the control solenoids, the valve is set to crossover or parallel position. If no current is flowing through the control solenoids, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way solenoid valve with floating position (i) p2_1_4_5   
4/3-way solenoid valve with floating position (ii)
4/3-way solenoid valve with floating position (ii)
Component library
Hydraulic Components

p2_1_4_7.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/3-way solenoid valve with bypass position (i)
Component library
Solenoid-actuated Directional Valves
In normal position the connections A and B are closed and P to T opened. When actuated by the control solenoids, the valve is set to parallel or crossover position. If no current is flowing through the control solenoids, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way solenoid valve with bypass position (ii) p2_1_4_8   [110]  4/3-way valve with pump bypass (1) p3_1_8_23   
4/3-way solenoid valve with bypass position (i)
4/3-way solenoid valve with bypass position (i)
Component library
Hydraulic Components

p2_1_4_8.ct
Component library < Hydraulic Components < Solenoid-actuated Directional Valves < 4/3-way solenoid valve with bypass position (ii)
Component library
Solenoid-actuated Directional Valves
In normal position the connections A and B are closed and P to T opened. When actuated by the control solenoids, the valve is set to crossover or parallel position. If no current is flowing through the control solenoids, the valve can be manually actuated.   This valve is derived from a configurable 4/n way valve p2_1_2_3. You find this valve in the component library “Frequently used Way Valves”, under the Library menu.   
Related Topics  Configurable 4/n way valve p2_1_2_3   4/3-way solenoid valve with bypass position (i) p2_1_4_7   [110]  4/3-way valve with pump bypass (1) p3_1_8_23   
4/3-way solenoid valve with bypass position (ii)
4/3-way solenoid valve with bypass position (ii)
Component library
Hydraulic Components

p2_1_5.ct
Component library < Hydraulic Components < Shutoff Valves
Component library
Component library
Hydraulic Components
Shutoff Valves
Shutoff Valves
Shutoff valve
Check valve
Check valve, spring loaded
Check valve with pilot control
Check valve with pilot control, spring loaded 
Pilot to close check valve
Pilot to close check valve, spring loaded
Shuttle valve
Two-pressure valve

p2_1_5_1.ct
Component library < Hydraulic Components < Shutoff Valves < Shutoff valve
Component library
Shutoff Valves
The shutoff valve can be manually opened or closed. The hydraulic resistance relates to the completely opened valve.   Adjustable parameters  	Opening level:	0 ... 100 %	(100)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.0625)  
Shutoff valve
Shutoff valve
Component library
Hydraulic Components

p2_1_5_2.ct
Component library < Hydraulic Components < Shutoff Valves < Check valve
Component library
Shutoff Valves
If the inlet pressure at A is higher than the outlet pressure at B, then the check valve allows the flow to pass, otherwise it blocks the flow.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Check valve, spring loaded p2_1_5_3   Check valve with pilot control p2_1_5_4   Pilot to close check valve p2_1_5_6   [125]  Non-return valve (1) p3_1_9_1   [130]  Graetz block p3_1_9_6   
Check valve
Check valve
Component library
Hydraulic Components

p2_1_5_3.ct
Component library < Hydraulic Components < Shutoff Valves < Check valve, spring loaded
Component library
Shutoff Valves
If the inlet pressure at A is higher than the outlet pressure at B and the nominal pressure, then the check valve allows the flow to pass, otherwise it blocks the flow.  Adjustable parameters  	Nominal pressure:	0.001 ... 40 MPa	(0.1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Check valve p2_1_5_2   Check valve with pilot control, spring loaded  p2_1_5_5   Pilot to close check valve, spring loaded p2_1_5_7   [125]  Non-return valve (1) p3_1_9_1   [130]  Graetz block p3_1_9_6   
Check valve, spring loaded
Check valve, spring loaded
Component library
Hydraulic Components

p2_1_5_4.ct
Component library < Hydraulic Components < Shutoff Valves < Check valve with pilot control
Component library
Shutoff Valves
If the input pressure is higher than the output pressure, the check valve opens. Otherwise it is shut. In addition, the check valve can be opened via a control line, allowing flow in both directions.  Adjustable parameters  	Area ratio:	1 ... 10 	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Check valve p2_1_5_2   Pilot to close check valve p2_1_5_6   [131]  Delockable non-return valve (1) p3_1_9_7   [134]  Circuit diagram: Delockable non-return valve p3_1_9_10   [135]  Delockable non-return valve p3_1_9_11   
Check valve with pilot control
Check valve with pilot control
Component library
Hydraulic Components

p2_1_5_5.ct
Component library < Hydraulic Components < Shutoff Valves < Check valve with pilot control, spring loaded 
Component library
Shutoff Valves
If the input pressure is higher than the output and nominal pressure, the check valve opens. Otherwise it is shut. In addition, the check valve can be opened via a control line, allowing flow in both directions.  Adjustable parameters  	Nominal pressure:	0.001 ... 40 MPa	(0.1)  	Area ratio:	1 ... 10 	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Check valve with pilot control p2_1_5_4   Check valve, spring loaded p2_1_5_3   Pilot to close check valve, spring loaded p2_1_5_7   [131]  Delockable non-return valve (1) p3_1_9_7   [134]  Circuit diagram: Delockable non-return valve p3_1_9_10   [135]  Delockable non-return valve p3_1_9_11   
Check valve with pilot control, spring loaded 
Check valve with pilot control, spring loaded 
Component library
Hydraulic Components

p2_1_5_6.ct
Component library < Hydraulic Components < Shutoff Valves < Pilot to close check valve
Component library
Shutoff Valves
If the inlet pressure at A is higher than the outlet pressure at B, then the check valve allows the flow to pass, otherwise it blocks the flow. Additionally, the check valve can be closed using the pilot line X.  Adjustable parameters  	Area ratio:	1 ... 10 	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pilot to close check valve, spring loaded p2_1_5_7   Check valve p2_1_5_2   Check valve with pilot control p2_1_5_4   
Pilot to close check valve
Pilot to close check valve
Component library
Hydraulic Components

p2_1_5_7.ct
Component library < Hydraulic Components < Shutoff Valves < Pilot to close check valve, spring loaded
Component library
Shutoff Valves
If the inlet pressure at A is higher than the outlet pressure at B and the nominal pressure, then the check valve allows the flow to pass, otherwise it blocks the flow. Additionally, the check valve can be closed using the pilot line X.  Adjustable parameters  	Nominal pressure:	0.001 ... 40 MPa	(0.1)  	Area ratio:	1 ... 10 	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pilot to close check valve p2_1_5_6   Check valve, spring loaded p2_1_5_3   Check valve with pilot control, spring loaded  p2_1_5_5   
Pilot to close check valve, spring loaded
Pilot to close check valve, spring loaded
Component library
Hydraulic Components

p2_1_5_8.ct
Component library < Hydraulic Components < Shutoff Valves < Shuttle valve
Component library
Shutoff Valves
If one of the two input pressures is larger than zero, the shuttle valve opens (OR function) and the higher input pressure becomes the output pressure.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topic  Two-pressure valve p2_1_5_9   
Shuttle valve
Shuttle valve
Component library
Hydraulic Components

p2_1_5_9.ct
Component library < Hydraulic Components < Shutoff Valves < Two-pressure valve
Component library
Shutoff Valves
If both input pressures are larger than zero, the two-pressure valve opens (AND function) and the higher input pressure becomes the output pressure.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topic  Shuttle valve p2_1_5_8   
Two-pressure valve
Two-pressure valve
Component library
Hydraulic Components

p2_1_6.ct
Component library < Hydraulic Components < Pressure Control Valves
Component library
Component library
Hydraulic Components
Pressure Control Valves
Pressure Control Valves
Pressure relief valve
Pressure relief valve with pilot control
Pressure relief valve with pilot control
Shutoff/counteracting valve
2-way pressure reducing valve
2-way pressure reducing valve, adjustable
3-way pressure reducing valve
Closing pressure compensator
Closing pressure compensator, adjustable
Opening pressure compensator
Opening pressure compensator, adjustable
Opening cartridge valve
Closing cartridge valve

p2_1_6_1.ct
Component library < Hydraulic Components < Pressure Control Valves < Pressure relief valve
Component library
Pressure Control Valves
In normal position the valve is closed. If the opening pressure is reached at P, T opens. When the pressure drops below the preset level, the valve closes again. The flow direction is indicated by the arrow.   The hydraulic resistance relates to the completely opened valve.   Adjustable parameters  	Nominal pressure:	0 ... 40 MPa	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve with pilot control p2_1_6_3   Shutoff/counteracting valve p2_1_6_4   Opening pressure compensator, adjustable p2_1_6_11   [59]  Pressure relief valve (1) p3_1_7_1   
Pressure relief valve
Pressure relief valve
Component library
Hydraulic Components

p2_1_6_10.ct
Component library < Hydraulic Components < Pressure Control Valves < Opening pressure compensator
Component library
Pressure Control Valves
The pressure compensator represents a pressure dependent hydraulic resistance. The pressure compensator opens when the pressure difference X-Y exceeds the nominal pressure. A pressure relief valve is implemented by the combination of connections P and X. The pressure balance is also a component of 3-way flow control valves.   The nominal pressure setting of the real components is component dependent and cannot be changed.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0.01 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Opening pressure compensator, adjustable p2_1_6_11   Closing pressure compensator p2_1_6_8   Pressure relief valve p2_1_6_1   3-way flow control valve p2_1_8_7   
Opening pressure compensator
Opening pressure compensator
Component library
Hydraulic Components

p2_1_6_11.ct
Component library < Hydraulic Components < Pressure Control Valves < Opening pressure compensator, adjustable
Component library
Pressure Control Valves
The pressure compensator represents a pressure dependent hydraulic resistance. The pressure compensator opens when the pressure difference X-Y exceeds the nominal pressure. A pressure relief valve is implemented by the combination of connections P and X.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0.01 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Opening pressure compensator p2_1_6_10   Closing pressure compensator, adjustable p2_1_6_9   Pressure relief valve p2_1_6_1   
Opening pressure compensator, adjustable
Opening pressure compensator, adjustable
Component library
Hydraulic Components

p2_1_6_12.ct
Component library < Hydraulic Components < Pressure Control Valves < Opening cartridge valve
Component library
Pressure Control Valves
The 2/2-way cartridge valve is a 2/2-way valve. It is fitted with two working ports and the two switch positions “closed” and “open”. Whether or not the cartridge valve is open or closed depends on the effective areas A, B and X, the adjacent pressures pA, pB and pX, as well as the spring force. A+B=X is valid.   If pA*A + pB*B > pX*X + F, then the valve opens, otherwise it is closed.   The valve therefore operates purely pressure dependent and can, with the appropriate control, assume directional-, flow- and pressure functions. The spring force is specified by means of the nominal pressure. This is the minimum pressure, with pressureless connections at B and X, necessary at connection A to open the valve.   Whether the valve has one (A=B) or two (A <> B) effective areas can be specified in the properties window. The relevant symbol is automatically depicted.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Area:	0 ... 100 qcm	(6)  	Nominal pressure:	0 ... 1 MPa	(0.1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.001)  
Related Topic  Closing cartridge valve p2_1_6_13   
Opening cartridge valve
Opening cartridge valve
Component library
Hydraulic Components

p2_1_6_13.ct
Component library < Hydraulic Components < Pressure Control Valves < Closing cartridge valve
Component library
Pressure Control Valves
The 2/2-way cartridge valve is a 2/2-way valve. It is fitted with two working ports and the two switch positions “closed” and “open”. Whether or not the cartridge valve is open or closed depends on the effective areas A and X, the adjacent pressures pA, and pX, as well as the spring force. A=X is valid.   If pA*A > pX*X + F, then the valve closes, otherwise it is open.   The valve therefore operates purely pressure dependent and can, with the appropriate control, assume directional-, flow- and pressure functions. The spring force is specified by means of the nominal pressure. This is the minimum pressure, with pressureless connections at B and X, necessary at connection A to open the valve.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Area:	0 ... 100 qcm	(6)  	Nominal pressure:	0 ... 1 MPa	(0.1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.001)  
Related Topic  Opening cartridge valve p2_1_6_12   
Closing cartridge valve
Closing cartridge valve
Component library
Hydraulic Components

p2_1_6_2.ct
Component library < Hydraulic Components < Pressure Control Valves < Pressure relief valve with pilot control
Component library
Pressure Control Valves
In normal position the valve is closed. If the opening pressure is reached at P, T opens. When the pressure drops below the preset level, the valve closes again. In simple terms, the pilot pressure is generated by the input pressure. The flow direction is indicated by the arrow.   The pilot operated pressure relief valve consists of a pilot stage and a main stage. When open, there is less volumetric flow at the pilot stage that leads internally to connection T.   The hydraulic resistance relates to the completely opened valve.   Adjustable parameters  	Nominal pressure:	0 ... 40 MPa	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve p2_1_6_1   Pressure relief valve with pilot control p2_1_6_3   
Pressure relief valve with pilot control
Pressure relief valve with pilot control
Component library
Hydraulic Components

p2_1_6_3.ct
Component library < Hydraulic Components < Pressure Control Valves < Pressure relief valve with pilot control
Component library
Pressure Control Valves
The valve is closed in the idle position. The hydraulic fluid drains off at T, when the pressure difference at the connections P and T exceeds the nominal pressure. If the pressure falls below the preset value, the valve closes again. The flow direction is marked with an arrow.   The pilot operated pressure relief valve consists of a pilot stage and a main stage. When open, there is less volumetric flow at the pilot stage that leads to connection Y.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0 ... 40 MPa	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve p2_1_6_1   Pressure relief valve with pilot control p2_1_6_2   Proportional pressure relief valve, piloted p2_1_9_5   
Pressure relief valve with pilot control
Pressure relief valve with pilot control
Component library
Hydraulic Components

p2_1_6_4.ct
Component library < Hydraulic Components < Pressure Control Valves < Shutoff/counteracting valve
Component library
Pressure Control Valves
If the opening pressure is reached at the control line connection, the valve opens from P to T.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0 ... 40 MPa	(5)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve p2_1_6_1   Opening pressure compensator, adjustable p2_1_6_11   [68]  PRV, externally controlled (1) p3_1_7_10   
Shutoff/counteracting valve
Shutoff/counteracting valve
Component library
Hydraulic Components

p2_1_6_5.ct
Component library < Hydraulic Components < Pressure Control Valves < 2-way pressure reducing valve
Component library
Pressure Control Valves
The pressure regulator valve regulates the pressure at connection A to the preset operating pressure and equalizes the pressure fluctuations. The valve closes when the pressure at connection A exceeds the operating pressure. The setting of the real components is component dependent and cannot be changed.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0.01 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  2-way pressure reducing valve, adjustable p2_1_6_6   3-way pressure reducing valve p2_1_6_7   Closing pressure compensator p2_1_6_8   [73]  2-way pressure regulator (1) p3_1_7_15   
2-way pressure reducing valve
2-way pressure reducing valve
Component library
Hydraulic Components

p2_1_6_6.ct
Component library < Hydraulic Components < Pressure Control Valves < 2-way pressure reducing valve, adjustable
Component library
Pressure Control Valves
The pressure regulator valve regulates the pressure at connection A to the preset operating pressure and equalizes the pressure fluctuations. The valve closes when the pressure at connection A exceeds the operating pressure.  Adjustable parameters  	Nominal pressure:	0.01 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  2-way pressure reducing valve p2_1_6_5   3-way pressure reducing valve p2_1_6_7   Closing pressure compensator, adjustable p2_1_6_9   [73]  2-way pressure regulator (1) p3_1_7_15   
2-way pressure reducing valve, adjustable
2-way pressure reducing valve, adjustable
Component library
Hydraulic Components

p2_1_6_7.ct
Component library < Hydraulic Components < Pressure Control Valves < 3-way pressure reducing valve
Component library
Pressure Control Valves
The pressure reducing valve maintains a constant output pressure despite fluctuating input pressure. The hydraulic fluid is drained off at T when the pressure at connection A exceeds the operating pressure.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve p2_1_6_1   2-way pressure reducing valve, adjustable p2_1_6_6   [80]  3-way pressure regulator (1) p3_1_7_22   [84]  3-way pressure regulator p3_1_7_26   
3-way pressure reducing valve
3-way pressure reducing valve
Component library
Hydraulic Components

p2_1_6_8.ct
Component library < Hydraulic Components < Pressure Control Valves < Closing pressure compensator
Component library
Pressure Control Valves
The pressure compensator represents a pressure dependent hydraulic resistance. The pressure compensator closes when the pressure difference X-Y exceeds the nominal pressure. A pressure regulating valve is implemented by the combination of connections A and X. The pressure balance is also a component of 2-way flow control valves.   The nominal pressure setting of the real components is component dependent and cannot be changed.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0.01 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Closing pressure compensator, adjustable p2_1_6_9   2-way pressure reducing valve p2_1_6_5   2-way flow control valve p2_1_8_6   Opening pressure compensator p2_1_6_10   [146]  2-way flow control valve (1) p3_1_10_7   
Closing pressure compensator
Closing pressure compensator
Component library
Hydraulic Components

p2_1_6_9.ct
Component library < Hydraulic Components < Pressure Control Valves < Closing pressure compensator, adjustable
Component library
Pressure Control Valves
The pressure compensator represents a pressure dependent hydraulic resistance. The pressure compensator closes when the pressure difference X-Y exceeds the nominal pressure. A pressure regulating valve is implemented by the combination of the connections A and X.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal pressure:	0.01 ... 40 MPa	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Closing pressure compensator p2_1_6_8   2-way pressure reducing valve, adjustable p2_1_6_6   
Closing pressure compensator, adjustable
Closing pressure compensator, adjustable
Component library
Hydraulic Components

p2_1_7.ct
Component library < Hydraulic Components < Pressure Switches
Component library
Component library
Hydraulic Components
Pressure Switches
Pressure Switches
Analog pressure sensor

p2_1_7_1.ct
Component library < Hydraulic Components < Pressure Switches < Analog pressure sensor
Component library
Pressure Switches
The pressure switch takes the pressure and actuates the associated electrical pressure switch if the preset switching pressure is exceeded.  Adjustable parameters  	Switching pressure:	0.0001 ... 35 MPa	(3)  
Related Topics  Coupling Hydraulics, Electrics and Mechanics 49   Pressure switch (break) p2_2_8_1   
Analog pressure sensor
Analog pressure sensor
Component library
Hydraulic Components

p2_1_8.ct
Component library < Hydraulic Components < Flow Control Valves
Component library
Component library
Hydraulic Components
Flow Control Valves
Flow Control Valves
Nozzle
Throttle valve
Orifice
Orifice, adjustable
One-way flow control valve
2-way flow control valve
3-way flow control valve
Flow divider valve

p2_1_8_1.ct
Component library < Hydraulic Components < Flow Control Valves < Nozzle
Component library
Flow Control Valves
The nozzle represents a hydraulic resistance.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Throttle valve p2_1_8_2   Orifice p2_1_8_3   [140]  Needle restrictor p3_1_10_1   [141]  Gap restrictor with helix p3_1_10_2   
Nozzle
Nozzle
Component library
Hydraulic Components

p2_1_8_2.ct
Component library < Hydraulic Components < Flow Control Valves < Throttle valve
Component library
Flow Control Valves
The setting of the throttle valve is set by means of a rotary knob. Please note that by the rotary knob no absolute resistance value can be set. This means that, in reality, different throttle valves can generate different resistance values despite identical settings.  Adjustable parameters  	Opening level:	0 ... 100 %	(100)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.045)  
Related Topics  Nozzle p2_1_8_1   Orifice p2_1_8_3   One-way flow control valve p2_1_8_5   [140]  Needle restrictor p3_1_10_1   [141]  Gap restrictor with helix p3_1_10_2   
Throttle valve
Throttle valve
Component library
Hydraulic Components

p2_1_8_3.ct
Component library < Hydraulic Components < Flow Control Valves < Orifice
Component library
Flow Control Valves
The orifice represents a hydraulic resistance.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Orifice, adjustable p2_1_8_4   Nozzle p2_1_8_1   [140]  Needle restrictor p3_1_10_1   [141]  Gap restrictor with helix p3_1_10_2   
Orifice
Orifice
Component library
Hydraulic Components

p2_1_8_4.ct
Component library < Hydraulic Components < Flow Control Valves < Orifice, adjustable
Component library
Flow Control Valves
The orifice represents a variable hydraulic resistance.  Adjustable parameters  	Opening level:	0 ... 100 %	(100)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Orifice p2_1_8_3   Throttle valve p2_1_8_2   [140]  Needle restrictor p3_1_10_1   [141]  Gap restrictor with helix p3_1_10_2   
Orifice, adjustable
Orifice, adjustable
Component library
Hydraulic Components

p2_1_8_5.ct
Component library < Hydraulic Components < Flow Control Valves < One-way flow control valve
Component library
Flow Control Valves
The setting of the One-way flow control valve is set by means of a rotary knob. A check valve (see check valve) is located parallel to the throttle valve. Please note that by the rotary knob no absolute resistance value can be set. This means that, in reality, different throttle valves can generate different resistance values despite identical settings.  Adjustable parameters  	Opening level:	0 ... 100 %	(100)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Throttle valve p2_1_8_2   Check valve p2_1_5_2   [144]  One-way flow control valve (1) p3_1_10_5   
One-way flow control valve
One-way flow control valve
Component library
Hydraulic Components

p2_1_8_6.ct
Component library < Hydraulic Components < Flow Control Valves < 2-way flow control valve
Component library
Flow Control Valves
If the pressure is sufficient, the preset flow is maintained to a constant level in the direction of the arrow.   The hydraulic resistance relates to the completely opened valve.  Adjustable parameters  	Nominal flow:	0.01 ... 500 l/min	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.019)  
Related Topics  3-way flow control valve p2_1_8_7   Flow divider valve p2_1_8_8   Throttle valve p2_1_8_2   Closing pressure compensator p2_1_6_8   [146]  2-way flow control valve (1) p3_1_10_7   
2-way flow control valve
2-way flow control valve
Component library
Hydraulic Components

p2_1_8_7.ct
Component library < Hydraulic Components < Flow Control Valves < 3-way flow control valve
Component library
Flow Control Valves
With sufficient pressure, the preset flow rate is kept constant in the direction of the arrow. The surplus hydraulic fluid is drained at connection T using a pressure compensator. The inlet pressure pA is load dependent, i.e it changes with the outlet pressure pB. Therefore a parallel circuit of several 3-way flow control valves is not possible. In this case, the inlet pressures would be defined by the valve with the lowest inlet pressure. Compared to the 2-way flow control valve, the 3-way flow control valve is admittedly more efficient in its energy consumption.   The hydraulic resistance relates to the completely closed pressure compensator.  Adjustable parameters  	Nominal flow:	0.01 ... 500 l/min	(1)  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  2-way flow control valve p2_1_8_6   Throttle valve p2_1_8_2   Opening pressure compensator p2_1_6_10   
3-way flow control valve
3-way flow control valve
Component library
Hydraulic Components

p2_1_8_8.ct
Component library < Hydraulic Components < Flow Control Valves < Flow divider valve
Component library
Flow Control Valves
The flow divider valve divides the flow from P into two equal flows at A and B. This is achieved using two measuring orifices and two variable control resistors. The control resistors are unified in a pressure compensator.   The hydraulic resistance relates to the resistance of the individual measuring orifices and control resistors.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  2-way flow control valve p2_1_8_6   3-way flow control valve p2_1_8_7   
Flow divider valve
Flow divider valve
Component library
Hydraulic Components

p2_1_9.ct
Component library < Hydraulic Components < Continuous valves
Component library
Component library
Hydraulic Components
Continuous valves
Continuous valves
4/3-way regulating valve
4/3-way proportional valve
Proportional throttle valve
Proportional pressure relief valve
Proportional pressure relief valve, piloted
Proportional pressure reducing valve, piloted

p2_1_9_1.ct
Component library < Hydraulic Components < Continuous valves < 4/3-way regulating valve
Component library
Continuous valves
The regulating valve transforms an analog electrical input signal into corresponding opening cross-sections at the outputs. The setpoint signal must be within the range -10 V to +10 V. At 0 V the hydraulic mid-position is adopted and the valve stops the flow (in relation to the null overlap).   The cross section area of the flow opening widens with increasing slide distance. How far the area, and with it the flow at the valve, changes depends on the shape and form of the control notches. A triangular shaped notch results in a progressive flow behavior, a rectangular shaped notch in a linear flow behavior.   The hydraulic resistance relates to a completely opened leading edge and the internal leakage relates to one leading edge as appropriate. The overlap of the leading edges can be specified relative to the maximal slide distance.   By the use of an integrated electronic position controller for the slide distance, beneficial static and dynamic characteristics are achieved that are manifested in a minimal hysteresis (less than 0,2 %) and a response time of less than 12 ms at a signal change of 0 - 100 %.   Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.14)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0.0026)  
Related Topics  Proportional valve solenoid, position controlled p2_6_1_3   Open-loop and Closed-loop Control by using Continuous Valves 814   
4/3-way regulating valve
4/3-way regulating valve
Component library
Hydraulic Components

p2_1_9_2.ct
Component library < Hydraulic Components < Continuous valves < 4/3-way proportional valve
Component library
Continuous valves
By use of a twin-channel proportional amplifier, the proportional valve transforms an analog electrical input signal into corresponding opening cross-sections at the outputs. The setpoint signal must be within the range -10 V to +10 V. At 0 V the hydraulic mid-position is adopted and the valve stops the flow (in relation to the null overlap).   The cross section area of the flow opening widens by increasing slide distance. How far the area, and with it the flow at the valve, changes depends on the shape and form of the control notches. A triangular shaped notch results in a progressive flow behavior, a rectangular shaped notch in a linear flow behavior.   The hydraulic resistance relates to a completely opened leading edge and the internal leakage relates to one leading edge as appropriate. The overlap of the leading edges can be specified relative to the maximal slide distance.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.32)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0.01)  
Related Topics  Proportional amplifier, 2-channel p2_6_1_5   Open-loop and Closed-loop Control by using Continuous Valves 814   
4/3-way proportional valve
4/3-way proportional valve
Component library
Hydraulic Components

p2_1_9_3.ct
Component library < Hydraulic Components < Continuous valves < Proportional throttle valve
Component library
Continuous valves
In order to alter the flow rate through the valve, the cross section of the throttle valve is electrically manipulated with the assistance of a proportional amplifier. The control voltage must be between 0 V and 10 V. The deflection of the slide is proportional to the applied voltage. At 0 V the valve is completely closed (in relation to the null overlap).   The hydraulic resistance relates to the completely opened valve. The overlap of the leading edges can be specified relative to the maximal slide distance.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  	Internal leakage:	0 ... 100 l/(min*MPa)	(0)  
Related Topics  Throttle valve p2_1_8_2   Proportional amplifier, 1-channel p2_6_1_4   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional throttle valve
Proportional throttle valve
Component library
Hydraulic Components

p2_1_9_4.ct
Component library < Hydraulic Components < Continuous valves < Proportional pressure relief valve
Component library
Continuous valves
The proportional pressure relief valve, with the assistance of a proportional amplifier, is a continuous, electrically adjustable pressure relief valve. The control piston has two adjacent areas exposed to pressure. The first area is exposed to the pressure at connection P, the other to connection T. If the magnet is not supplied with electricity, then the piston is fully retracted and the complete passage from connection P to connection T is free. The proportional magnet creates a force proportional to its magnetic current, which moves the control piston according to the balance of the adjacent forces (magnetic force, spring force and pressures).   The control voltage must be in the range 0 V to 10 V. The minimum nominal pressure defines the opening pressure through the spring force at 0 V. The maximum nominal pressure defines the opening pressure at 10 V. The hydraulic resistance relates to the completely opened main stage leading edge.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve p2_1_6_1   Proportional pressure relief valve, piloted p2_1_9_5   Proportional amplifier, 1-channel p2_6_1_4   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional pressure relief valve
Proportional pressure relief valve
Component library
Hydraulic Components

p2_1_9_5.ct
Component library < Hydraulic Components < Continuous valves < Proportional pressure relief valve, piloted
Component library
Continuous valves
The pilot operated pressure relief valve consists of a pilot stage with poppet valve and a main stage with control slide valve. The pressure at connection P acts upon the pilot poppet via a drilling in the control slide valve.   If the force of the proportional magnet is greater than the pressure exercised at connection P, then the pilot stage remains closed. A spring keeps the main stage poppet valve closed and the flow rate is null.   If the force, that the pressure exercises, exceeds the closing force of the pilot poppet, then this opens. A lower flow rate develops from connection P to connection Y. The flow of fluid causes a pressure loss at the throttle valve inside the control slide valve. Thus the pressure at the spring side is lower than the pressure at connection P. Due to the pressure difference, the control slide valve opens so far until the spring force re-establishes an equilibrium of forces and the valve is perfused from P to T.   The control voltage must be between 0 V and 10 V. The minimum nominal pressure defines the opening pressure at the pilot stage via the spring force at 0 V. The maximum nominal pressure defines the opening pressure at 10 V. The hydraulic resistance relates to the completely opened main stage leading edge.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Pressure relief valve with pilot control p2_1_6_3   Proportional amplifier, 1-channel p2_6_1_4   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional pressure relief valve, piloted
Proportional pressure relief valve, piloted
Component library
Hydraulic Components

p2_1_9_6.ct
Component library < Hydraulic Components < Continuous valves < Proportional pressure reducing valve, piloted
Component library
Continuous valves
The pilot operated proportional pressure regulator valve consists of a pilot stage with poppet valve and a main stage with control slide valve. The pressure at connection A acts upon the pilot poppet via a drilling in the control slide valve. The proportional magnet exercises the electrically adjustable counter force with the assistance of a proportional amplifier.   If the pressure at connection A is below the preset value, then the pilot control remains closed. The pressure on both sides of the control slide valve is equal. A spring holds the main stage control slide valve open and the hydraulic fluid flow freely from connection P to connection A.   If the pressure at connection A exceeds the preset value, then the pilot stage opens causing less volumetric flow to flow to connection A. The pressure falls at the throttle valve inside the control slide valve. Thus the pressure at the spring side is lower than the pressure at connection A. Due to the pressure difference, the control slide valve closes so far until the spring force re-establishes an equilibrium of forces. As a result, the flow resistance at the control edge between connections P and A increases and the pressure at connection A sinks.   The control voltage must be between 0 V and 10 V. The minimum nominal pressure defines the opening pressure at the pre stage via the spring force at 0 V. The maximum nominal pressure defines the opening pressure at 10 V. The hydraulic resistance relates to the completely opened main stage leading edge.  Adjustable parameters  	Hydraulic resistance:	1e-7 ... 100 MPa*min2/l2	(0.01)  
Related Topics  Proportional amplifier, 1-channel p2_6_1_4   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional pressure reducing valve, piloted
Proportional pressure reducing valve, piloted
Component library
Hydraulic Components

p2_2.ct
Component library < Electrical Components
Component library
Electrical Components
Component library
Electrical Components
Power Supply
Actuators / Signal Devices
Measuring Instruments / Sensors
General Switches
Delay Switches
Limit Switches
Manually Operated Switches
Pressure Switches
Proximity Switches
Relays
Controller
EasyPort/OPC/DDE Components

p2_2_1.ct
Component library < Electrical Components < Power Supply
Component library
Component library
Electrical Components
Power Supply
Power Supply
Electrical connection 0V
Electrical connection 24V
Function generator
Setpoint value card
Connection (electrical)
Line (electrical)
T-junction (electrical)

p2_2_10.ct
Component library < Electrical Components < Relays
Component library
Component library
Electrical Components
Relays
Relays
Relay
Relay with switch-on delay
Relay with switch-off delay
Relay counter
Starting current limiter

p2_2_10_1.ct
Component library < Electrical Components < Relays < Relay
Component library
Relays
The relay picks up immediately when current is supplied and drops out immediately when current is removed.  
Related Topics  Break switch p2_2_4_1   Make switch p2_2_4_2   Changeover switch p2_2_4_3   Coupling Hydraulics, Electrics and Mechanics 49   
Relay
Relay
Component library
Electrical Components

p2_2_10_2.ct
Component library < Electrical Components < Relays < Relay with switch-on delay
Component library
Relays
The relay picks up after a preset time when current is supplied and drops out immediately when current is removed.  Adjustable parameters  	Delay time:	0 ... 100 s	(5)  
Related Topics  Break switch (switch-on delayed) p2_2_5_1   Make switch (switch-on delayed) p2_2_5_2   Changeover switch (switch-on delayed) p2_2_5_3   Coupling Hydraulics, Electrics and Mechanics 49   
Relay with switch-on delay
Relay with switch-on delay
Component library
Electrical Components

p2_2_10_3.ct
Component library < Electrical Components < Relays < Relay with switch-off delay
Component library
Relays
The relay picks up immediately when current is supplied and drops out after a preset time when current is removed.  Adjustable parameters  	Delay time:	0 ... 100 s	(5)  
Related Topics  Break switch (switch-off delayed) p2_2_5_4   Make switch (switch-off delayed) p2_2_5_5   Changeover switch (switch-off delayed) p2_2_5_6   Coupling Hydraulics, Electrics and Mechanics 49   
Relay with switch-off delay
Relay with switch-off delay
Component library
Electrical Components

p2_2_10_4.ct
Component library < Electrical Components < Relays < Relay counter
Component library
Relays
The relay picks up after a predefined number of current pulses has/have been counted between the connections A1 and A2. If a potential is supplied between the connections R1 and R2, the counter is reset to its predefined value.   In the Simulation Mode the relay counter can also be reset by clicking on it.   Adjustable parameters  	Counter:	0 ... 9999 pulses	(5)  
Related Topics  Break switch p2_2_4_1   Make switch p2_2_4_2   Changeover switch p2_2_4_3   Coupling Hydraulics, Electrics and Mechanics 49   
Relay counter
Relay counter
Component library
Electrical Components

p2_2_10_5.ct
Component library < Electrical Components < Relays < Starting current limiter
Component library
Relays
The starting current limiter consists essentially of a relay, whose coil is situated between the connections IN and 0V, and whose switch contact is situated between the connections 24V and OUT. An electronic longitudinal controller restricts, with a switched relay contact, the current flow to the preset value for the specified duration.   The starting current limiter is usually deployed in combination with the electric motor p2_2_2_1.   Adjustable parameters  	Duration:	1 ... 10000 ms	(50)  	Max. current:	0.1 ... 100 A	(2)  
Related Topic  DC motor p2_2_2_1   
Starting current limiter
Starting current limiter
Component library
Electrical Components

p2_2_11.ct
Component library < Electrical Components < Controller
Component library
Component library
Electrical Components
Controller
Controller
Comparator
PID controller
Status controller

p2_2_11_1.ct
Component library < Electrical Components < Controller < Comparator
Component library
Controller
The comparator is a discontinuous (switching) two-step action controller with differential gap (hysteresis). When activated, it delivers a predefined voltage signal. The switch-on value for the activation is defined by nominal value + 1/2 hysteresis and the switch-off value by nominal value - 1/2 hysteresis. The comparator requires a power supply of 24 V.  Adjustable parameters  	Set value voltage:	-10 ... 10 V	(5)  	Hysteresis:	0 ... 5 V	(1)  
Comparator
Comparator
Component library
Electrical Components

p2_2_11_2.ct
Component library < Electrical Components < Controller < PID controller
Component library
Controller
The PID-Controller is a continuous controller consisting of three control elements: Proportional, Integral and Derivative. The adjustable parameters refer to the PID-Controller in the Technology Package TP511 hydraulic control from Festo Didactic.   The output voltage restriction can be set within the range (i) -10 V to + 10 V or (ii) 0 V to +10 V. In the range (i), a manipulated variable offset from -7 V to + 7 V can be specified, and in the range (ii) a manipulated variable offset from 1.5 V to 8.5 V can be specified. The PID-controller requires a power supply of 24 V.  Adjustable parameters  	Proportional gain:	0 ... 1000 	(1)  	Integral gain:	0 ... 1000 1/s	(0)  	Derivation gain:	0 ... 1000 ms	(0)  
Related Topics  Status controller p2_2_11_3   Open-loop and Closed-loop Control by using Continuous Valves 814   
PID controller
PID controller
Component library
Electrical Components

p2_2_11_3.ct
Component library < Electrical Components < Controller < Status controller
Component library
Controller
The status controller is especially suitable for controlling pneumatic positioning circuits. A pneumatic positioning circuit counts to the controlled systems that can only be unsatisfactorily controlled with a standard controller. Three parameters can be attributed to the present status controller: position, speed and acceleration of the piston. The controller is therefore referred to as a “triple loop” controller. Speed and acceleration are not measured with sensors out of cost reasons. They are calculated by the controller from the differences in position. The adjustable parameters refer to the status controller in the Technology Package TP511 Closed-loop hydraulics from Festo Didactic.   The output voltage restriction can be set within the range (i) -10 V to + 10 V or (ii) 0 V to +10 V. In the range (i), a manipulated variable offset from -7 V to + 7 V can be specified, and in the range (ii) a manipulated variable offset from 1.5 V to 8.5 V can be specified. The status controller requires a power supply of 24 V.  Adjustable parameters  	Deviation gain:	0 ... 10 	(1)  	Velocity damping:	0 ... 100 ms	(0)  	Acceleration damping:	0 ... 10 ms2	(0)  	Total gain:	0 ... 1000 	(1)  
Related Topics  PID controller p2_2_11_2   Open-loop and Closed-loop Control by using Continuous Valves 814   
Status controller
Status controller
Component library
Electrical Components

p2_2_12.ct
Component library < Electrical Components < EasyPort/OPC/DDE Components
Component library
Component library
Electrical Components
EasyPort/OPC/DDE Components
EasyPort/OPC/DDE Components
FluidSIM Output Port
FluidSIM Input Port

p2_2_12_1.ct
Component library < Electrical Components < EasyPort/OPC/DDE Components < FluidSIM Output Port
Component library
EasyPort/OPC/DDE Components
Communication with the EasyPort-Hardware and other applications is implemented with the FluidSIM-Output.   
Related Topics  FluidSIM Input Port p2_2_12_2   OPC and DDE communication with Other Applications 59   
FluidSIM Output Port
FluidSIM Output Port
Component library
Electrical Components

p2_2_12_2.ct
Component library < Electrical Components < EasyPort/OPC/DDE Components < FluidSIM Input Port
Component library
EasyPort/OPC/DDE Components
The FluidSIM input realizes the communication with other applications. Communication with the EasyPort-Hardware and other applications is implemented with the FluidSIM-Output.   
Related Topics  FluidSIM Output Port p2_2_12_1   OPC and DDE communication with Other Applications 59   
FluidSIM Input Port
FluidSIM Input Port
Component library
Electrical Components

p2_2_1_1.ct
Component library < Electrical Components < Power Supply < Electrical connection 0V
Component library
Power Supply
0V connection of the power supply.  
Related Topic  Electrical connection 24V p2_2_1_2   
Electrical connection 0V
Electrical connection 0V
Component library
Electrical Components

p2_2_1_2.ct
Component library < Electrical Components < Power Supply < Electrical connection 24V
Component library
Power Supply
24V connection of the power supply.  
Related Topic  Electrical connection 0V p2_2_1_1   
Electrical connection 24V
Electrical connection 24V
Component library
Electrical Components

p2_2_1_3.ct
Component library < Electrical Components < Power Supply < Function generator
Component library
Power Supply
The function generator is a voltage source that can create constant, rectangle, sine and triangle signals. The voltage range is restricted to -10 V to +10 V. The frequency, the amplitude and the Y-offset of the signal can be set within this range.   A voltage profile can be additionally specified. Data points can be set interactively with a mouse-click in the relevant graphic field. These can then be combined to a closed polygon. Alternatively, existing data points can be marked and both numeric values for the time and the corresponding voltage can be entered in the input fields. If the option “loop” is selected, then the voltage profile is started again.  Adjustable parameters  	Frequency:	0 ... 100 Hz	(1)  	Amplitude:	0 ... 10 V	(5)  	y offset:	-10 ... 10 V	(5)  
Related Topic  Setpoint value card p2_2_1_4   
Function generator
Function generator
Component library
Electrical Components

p2_2_1_4.ct
Component library < Electrical Components < Power Supply < Setpoint value card
Component library
Power Supply
Voltage profiles in the range -10 V to +10 V can be created using the setpoint value card. Up to 8 setpoints W1 to W8 can be specified in the voltage range -10 V to +10 V. The setpoint card requires a power supply of 24 V.   The increase from the current setpoint to the next setpoint is defined using 4 ramps R1 to R4 with values between 0 s/V and 10 s/V, i.e. a low ramp value signifies a large increase, whereas a high ramp value results in a small increase. The active ramp is defined as follows: R1 by a positive increase of 0 V, R2 by a negative increase up to 0 V, R3 by a negative increase of 0 V and R4 by a positive increase up to 0 V.   Three operating modes can be selected: “Wait for switching time”, “Advance setpoints” and “External control”.   In operating mode “Wait for switching time” the setpoints are sequentially advanced when the preset change over time has expired.   If “Advance setpoints” is selected then, upon attaining the active setpoint, the next setpoint is started without delay.   In operating mode “External control” the selection of the active setpoint is effected by gating the inputs I1, I2 and I3 with at least 15 V. The corresponding setpoint is selected by means of the specified bit table. During the process, the internal switching time is inactive.   W1: I1= 0, I2= 0, I3= 0  W2: I1= 1, I2= 0, I3= 0  W3: I1= 0, I2= 1, I3= 0  W4: I1= 1, I2= 1, I3= 0  W5: I1= 0, I2= 0, I3= 1  W6: I1= 1, I2= 0, I3= 1  W7: I1= 0, I2= 1, I3= 1  W8: I1= 1, I2= 1, I3= 1    
Related Topic  Function generator p2_2_1_3   
Setpoint value card
Setpoint value card
Component library
Electrical Components

p2_2_1_5.ct
Component library < Electrical Components < Power Supply < Connection (electrical)
Component library
Power Supply
An electric connection is a place where an electric line can be attached to. To simplify the line drawing process, a connection appears as a small circle in Edit Mode.   Note that at each electric connection values for the voltage and current can be displayed.  
Related Topics  Line (electrical) p2_2_1_6   T-junction (electrical) p2_2_1_7   Creating new Circuit Diagrams 19   Insertion of T-connections 43   Drawing Errors 452   Displaying Quantity Values 45   
Connection (electrical)
Connection (electrical)
Component library
Electrical Components

p2_2_1_6.ct
Component library < Electrical Components < Power Supply < Line (electrical)
Component library
Power Supply
A electrical line links two electrical connections. Note that a electrical connection may be a simple electrical connection p2_2_1_5 or a T-junction p2_2_1_7. A electrical line causes no voltage drop, i. e., it has no electrical resistance.  
Related Topic  Creating new Circuit Diagrams 19   
Line (electrical)
Line (electrical)
Component library
Electrical Components

p2_2_1_7.ct
Component library < Electrical Components < Power Supply < T-junction (electrical)
Component library
Power Supply
A T-junction joins up to four electrical lines p2_2_1_6, thus having a single voltage potential. Note that T-junctions are introduced automatically by FluidSIM when dropping the line drawing cursor onto another line in Edit Mode.  
Related Topics  Connection (electrical) p2_2_1_5   Creating new Circuit Diagrams 19   
T-junction (electrical)
T-junction (electrical)
Component library
Electrical Components

p2_2_2.ct
Component library < Electrical Components < Actuators / Signal Devices
Component library
Component library
Electrical Components
Actuators / Signal Devices
Actuators / Signal Devices
DC motor
Indicator light
Buzzer

p2_2_2_1.ct
Component library < Electrical Components < Actuators / Signal Devices < DC motor
Component library
Actuators / Signal Devices
The DC motor transforms electrical energy into mechanical energy. DC motors produce the continual rotation through repeated changes in the direction of current. The characteristics of the 24 V Dc motor relate to the motor used by the Festo Didactic conveyor belts.  Adjustable parameters  	No load speed:	10 ... 20000 1/min	(75)  	Torque:	0 ... 20 Nm	(0)  
Related Topics  Electrical connection 24V p2_2_1_2   Starting current limiter p2_2_10_5   
DC motor
DC motor
Component library
Electrical Components

p2_2_2_2.ct
Component library < Electrical Components < Actuators / Signal Devices < Indicator light
Component library
Actuators / Signal Devices
If current flows, the indicator light is displayed in the user-defined color.  Adjustable parameters  	Color:	16 standard colors 	(Yellow)  
Related Topic  Buzzer p2_2_2_3   
Indicator light
Indicator light
Component library
Electrical Components

p2_2_2_3.ct
Component library < Electrical Components < Actuators / Signal Devices < Buzzer
Component library
Actuators / Signal Devices
If current flows, a flashing ring around the buzzer is shown. Moreover, if “buzzer” is activated in the menu under Options- Sound..., the buzzer is activated if a sound hardware is installed.  
Related Topics  Indicator light p2_2_2_2   Sound Parameters 58   Technical Requirements 7   
Buzzer
Buzzer
Component library
Electrical Components

p2_2_3.ct
Component library < Electrical Components < Measuring Instruments / Sensors
Component library
Component library
Electrical Components
Measuring Instruments / Sensors
Measuring Instruments / Sensors
Voltmeter
Ammeter
Displacement encoder
Pressure sensor, analog
Flow meter, analog

p2_2_3_1.ct
Component library < Electrical Components < Measuring Instruments / Sensors < Voltmeter
Component library
Measuring Instruments / Sensors
With a voltmeter, the voltage between two positions in a circuit can be measured.  
Voltmeter
Voltmeter
Component library
Electrical Components

p2_2_3_2.ct
Component library < Electrical Components < Measuring Instruments / Sensors < Ammeter
Component library
Measuring Instruments / Sensors
With an ammeter, the amperage (current strength) of the current between two positions in a circuit can be measured.  
Ammeter
Ammeter
Component library
Electrical Components

p2_2_3_3.ct
Component library < Electrical Components < Measuring Instruments / Sensors < Displacement encoder
Component library
Measuring Instruments / Sensors
The displacement encoder is a slide potentiometer with longitudinal contact and no connecting-rods. It delivers a voltage signal that is proportional to the pick up position. The pick up position is determined by the piston stroke. The voltage range, which will depict the minimal and maximal piston position, can be defined within the range -10 V to +10 V by the user. The displacement encoder requires a power supply of at least 13 V.  
Related Topics  Configurable cylinder p2_1_10_1   Open-loop and Closed-loop Control by using Continuous Valves 814   
Displacement encoder
Displacement encoder
Component library
Electrical Components

p2_2_3_4.ct
Component library < Electrical Components < Measuring Instruments / Sensors < Pressure sensor, analog
Component library
Measuring Instruments / Sensors
This symbol represents the electrical part of the Analog-pressure sensor p2_1_11_4   
Related Topics  Pressure sensor, analog p2_1_11_4   Coupling Hydraulics, Electrics and Mechanics 49   Open-loop and Closed-loop Control by using Continuous Valves 814   
Pressure sensor, analog
Pressure sensor, analog
Component library
Electrical Components

p2_2_3_5.ct
Component library < Electrical Components < Measuring Instruments / Sensors < Flow meter, analog
Component library
Measuring Instruments / Sensors
This symbol represents the electrical part of the Analog-flow meter p2_1_11_7   
Related Topics  Pressure sensor, analog p2_1_11_4   Coupling Hydraulics, Electrics and Mechanics 49   Open-loop and Closed-loop Control by using Continuous Valves 814   
Flow meter, analog
Flow meter, analog
Component library
Electrical Components

p2_2_4.ct
Component library < Electrical Components < General Switches
Component library
Component library
Electrical Components
General Switches
General Switches
Break switch
Make switch
Changeover switch

p2_2_4_1.ct
Component library < Electrical Components < General Switches < Break switch
Component library
General Switches
General break switch that is tailored depending on the type of component that actuates it.  For example, if the break switch is linked via a label to a switch-off delay relay p2_2_10_3, the break switch changes to a switch-off delay break switch p2_2_5_4 in the circuit diagram.  
Related Topics  Relay p2_2_10_1   Break switch (switch-on delayed) p2_2_5_1   Break switch (switch-off delayed) p2_2_5_4   Limit switch (break) p2_2_6_1   Switch with roll (break) p2_2_6_2   Reed contact (break) p2_2_6_3   Pressure switch (break) p2_2_8_1   Coupling Hydraulics, Electrics and Mechanics 49   Automatic Switch Altering 54   
Break switch
Break switch
Component library
Electrical Components

p2_2_4_2.ct
Component library < Electrical Components < General Switches < Make switch
Component library
General Switches
General make switch that is tailored according to the component that actuates it.  For example, if the make switch is linked via a label to a switch-on delayed relay p2_2_10_2, the make switch changes to a switch-on delayed make switch p2_2_5_2 in the circuit diagram.  
Related Topics  Relay p2_2_10_1   Make switch (switch-on delayed) p2_2_5_2   Make switch (switch-off delayed) p2_2_5_5   Limit switch (make) p2_2_6_4   Switch with roll (make) p2_2_6_5   Reed contact (make) p2_2_6_6   Pressure switch (make) p2_2_8_2   Coupling Hydraulics, Electrics and Mechanics 49   Automatic Switch Altering 54   
Make switch
Make switch
Component library
Electrical Components

p2_2_4_3.ct
Component library < Electrical Components < General Switches < Changeover switch
Component library
General Switches
General changeover switch that is tailored according to the component that actuates it.  For example, if the changeover switch is linked via a label to a switch-on delayed relay p2_2_10_2, the changeover switch changes to a switch-on delayed p2_2_5_3 changeover switch p2_2_5_3 in the circuit diagram.  
Related Topics  Relay p2_2_10_1   Changeover switch (switch-on delayed) p2_2_5_3   Changeover switch (switch-off delayed) p2_2_5_6   Limit switch (changeover) p2_2_6_7   Switch with roll (changeover) p2_2_6_8   Reed contact (changeover) p2_2_6_9   Pressure switch (changeover) p2_2_8_3   Coupling Hydraulics, Electrics and Mechanics 49   Automatic Switch Altering 54   
Changeover switch
Changeover switch
Component library
Electrical Components

p2_2_5.ct
Component library < Electrical Components < Delay Switches
Component library
Component library
Electrical Components
Delay Switches
Delay Switches
Break switch (switch-on delayed)
Make switch (switch-on delayed)
Changeover switch (switch-on delayed)
Break switch (switch-off delayed)
Make switch (switch-off delayed)
Changeover switch (switch-off delayed)

p2_2_5_1.ct
Component library < Electrical Components < Delay Switches < Break switch (switch-on delayed)
Component library
Delay Switches
Switch with delayed opening after pickup. Switch-on delayed break switches are created by using a general break switch p2_2_4_1 and setting a label.  
Related Topics  Relay with switch-on delay p2_2_10_2   Break switch (switch-off delayed) p2_2_5_4   Coupling Hydraulics, Electrics and Mechanics 49   
Break switch (switch-on delayed)
Break switch (switch-on delayed)
Component library
Electrical Components

p2_2_5_2.ct
Component library < Electrical Components < Delay Switches < Make switch (switch-on delayed)
Component library
Delay Switches
Switch with delayed closing after pickup. Switch-on delayed make switches are created by using a general make switch p2_2_4_2 and setting a label.  
Related Topics  Relay with switch-on delay p2_2_10_2   Make switch (switch-off delayed) p2_2_5_5   Coupling Hydraulics, Electrics and Mechanics 49   
Make switch (switch-on delayed)
Make switch (switch-on delayed)
Component library
Electrical Components

p2_2_5_3.ct
Component library < Electrical Components < Delay Switches < Changeover switch (switch-on delayed)
Component library
Delay Switches
Changeover switch with delayed changeover after pickup. Switch-on delayed changeover switches are created by using a general changeover switch p2_2_4_3 and setting a label.  
Related Topics  Relay with switch-on delay p2_2_10_2   Changeover switch (switch-off delayed) p2_2_5_6   Coupling Hydraulics, Electrics and Mechanics 49   
Changeover switch (switch-on delayed)
Changeover switch (switch-on delayed)
Component library
Electrical Components

p2_2_5_4.ct
Component library < Electrical Components < Delay Switches < Break switch (switch-off delayed)
Component library
Delay Switches
Switch with delayed closing after dropout. Switch-off delayed break switches are created by using a general break switch p2_2_4_1 and setting a label.  
Related Topics  Relay with switch-off delay p2_2_10_3   Break switch (switch-on delayed) p2_2_5_1   Coupling Hydraulics, Electrics and Mechanics 49   
Break switch (switch-off delayed)
Break switch (switch-off delayed)
Component library
Electrical Components

p2_2_5_5.ct
Component library < Electrical Components < Delay Switches < Make switch (switch-off delayed)
Component library
Delay Switches
Switch with delayed opening after dropout. Switch-off delayed make switches are created by using a general make switch p2_2_4_2 and setting a label.  
Related Topics  Relay with switch-off delay p2_2_10_3   Make switch (switch-on delayed) p2_2_5_2   Coupling Hydraulics, Electrics and Mechanics 49   
Make switch (switch-off delayed)
Make switch (switch-off delayed)
Component library
Electrical Components

p2_2_5_6.ct
Component library < Electrical Components < Delay Switches < Changeover switch (switch-off delayed)
Component library
Delay Switches
Changeover switch with delayed changeover after dropout. Switch-off delayed changeover switches are created by using a general changeover switch p2_2_4_3 and setting a label.  
Related Topics  Relay with switch-off delay p2_2_10_3   Changeover switch (switch-on delayed) p2_2_5_3   Coupling Hydraulics, Electrics and Mechanics 49   
Changeover switch (switch-off delayed)
Changeover switch (switch-off delayed)
Component library
Electrical Components

p2_2_6.ct
Component library < Electrical Components < Limit Switches
Component library
Component library
Electrical Components
Limit Switches
Limit Switches
Limit switch (break)
Switch with roll (break)
Reed contact (break)
Limit switch (make)
Switch with roll (make)
Reed contact (make)
Limit switch (changeover)
Switch with roll (changeover)
Reed contact (changeover)

p2_2_6_1.ct
Component library < Electrical Components < Limit Switches < Limit switch (break)
Component library
Limit Switches
Switch that is opened by a cam attached to the cylinder rod. The switch closes immediately when the cam has passed the switch. Limit switches are created by using a general break switch p2_2_4_1 and setting a label.  
Related Topics  Switches at Cylinders 52   Distance rule p2_6_1_7   
Limit switch (break)
Limit switch (break)
Component library
Electrical Components

p2_2_6_2.ct
Component library < Electrical Components < Limit Switches < Switch with roll (break)
Component library
Limit Switches
Switch that is opened by a cam attached to the cylinder rod. The switch closes immediately when the cam has passed the switch. Switches with roll are created by using a general break switch p2_2_4_1, setting a label and selecting the switch type in the component's properties dialog.  
Related Topics  Switches at Cylinders 52   Automatic Switch Altering 54   Distance rule p2_6_1_7   
Switch with roll (break)
Switch with roll (break)
Component library
Electrical Components

p2_2_6_3.ct
Component library < Electrical Components < Limit Switches < Reed contact (break)
Component library
Limit Switches
Switch that is opened by a cam attached to the cylinder rod. The switch closes immediately when the cam has passed the switch. Reed contacts are created by using a general break switch p2_2_4_1, setting a label and selecting the switch type in the component's properties dialog.  
Related Topics  Switches at Cylinders 52   Automatic Switch Altering 54   Distance rule p2_6_1_7   
Reed contact (break)
Reed contact (break)
Component library
Electrical Components

p2_2_6_4.ct
Component library < Electrical Components < Limit Switches < Limit switch (make)
Component library
Limit Switches
Switch that is closed by a cam attached to the cylinder rod. The switch opens immediately when the cam has passed the switch. Limit switches are created by using a general make switch p2_2_4_2 and setting a label.  
Related Topics  Switches at Cylinders 52   Distance rule p2_6_1_7   
Limit switch (make)
Limit switch (make)
Component library
Electrical Components

p2_2_6_5.ct
Component library < Electrical Components < Limit Switches < Switch with roll (make)
Component library
Limit Switches
Switch that is closed by a cam attached to the cylinder rod. The switch opens immediately when the cam has passed the switch. Switches with roll are created by using a general make switch p2_2_4_2, setting a label and selecting the switch type in the component's properties dialog.  
Related Topics  Switches at Cylinders 52   Automatic Switch Altering 54   Distance rule p2_6_1_7   
Switch with roll (make)
Switch with roll (make)
Component library
Electrical Components

p2_2_6_6.ct
Component library < Electrical Components < Limit Switches < Reed contact (make)
Component library
Limit Switches
Switch that is closed by a cam attached to the cylinder rod. The switch opens immediately when the cam has passed the switch. Reed contacts are created by using a general make switch p2_2_4_2, setting a label and selecting the switch type in the component's properties dialog.  
Related Topics  Switches at Cylinders 52   Automatic Switch Altering 54   Distance rule p2_6_1_7   
Reed contact (make)
Reed contact (make)
Component library
Electrical Components

p2_2_6_7.ct
Component library < Electrical Components < Limit Switches < Limit switch (changeover)
Component library
Limit Switches
Switch that is changed over by a cam attached to the cylinder rod. The switch changes back immediately when the cam has passed the switch. Limit switches are created by using a general changeover switch p2_2_4_3 and setting a label.  
Related Topics  Switches at Cylinders 52   Distance rule p2_6_1_7   
Limit switch (changeover)
Limit switch (changeover)
Component library
Electrical Components

p2_2_6_8.ct
Component library < Electrical Components < Limit Switches < Switch with roll (changeover)
Component library
Limit Switches
Switch that is changed over by a cam attached to the cylinder rod. The switch changes back immediately when the cam has passed the switch. Switches with roll are created by using a general changeover switch p2_2_4_3, setting a label and selecting the switch type in the component's properties dialog.  
Related Topics  Switches at Cylinders 52   Automatic Switch Altering 54   Distance rule p2_6_1_7   
Switch with roll (changeover)
Switch with roll (changeover)
Component library
Electrical Components

p2_2_6_9.ct
Component library < Electrical Components < Limit Switches < Reed contact (changeover)
Component library
Limit Switches
Switch that is changed over by a cam attached to the cylinder rod. The switch changes back immediately when the cam has passed the switch. Reed contacts are created by using a general changeover switch p2_2_4_3, setting a label and selecting the switch type in the component's properties dialog.  
Related Topics  Switches at Cylinders 52   Automatic Switch Altering 54   Distance rule p2_6_1_7   
Reed contact (changeover)
Reed contact (changeover)
Component library
Electrical Components

p2_2_7.ct
Component library < Electrical Components < Manually Operated Switches
Component library
Component library
Electrical Components
Manually Operated Switches
Manually Operated Switches
Pushbutton (break)
Pushbutton (make)
Pushbutton (changeover)
Detent switch (break)
Detent switch (make)
Detent switch (changeover)

p2_2_7_1.ct
Component library < Electrical Components < Manually Operated Switches < Pushbutton (break)
Component library
Manually Operated Switches
Switch that opens when actuated and closes immediately when released.   In FluidSIM switches can be actuated permanently (locked) when continuing to hold down the mouse button and pushing the Shift key. This permanent actuation is released by a simple click on the component.  
Related Topics  Detent switch (break) p2_2_7_4   Simultaneous Actuation of Several Components 39   
Pushbutton (break)
Pushbutton (break)
Component library
Electrical Components

p2_2_7_2.ct
Component library < Electrical Components < Manually Operated Switches < Pushbutton (make)
Component library
Manually Operated Switches
Switch that closes when actuated and opens immediately when released.   In FluidSIM switches can be actuated permanently (locked) when continuing to hold down the mouse button and pushing the Shift key. This permanent actuation is released by a simple click on the component.  
Related Topics  Detent switch (make) p2_2_7_5   Simultaneous Actuation of Several Components 39   
Pushbutton (make)
Pushbutton (make)
Component library
Electrical Components

p2_2_7_3.ct
Component library < Electrical Components < Manually Operated Switches < Pushbutton (changeover)
Component library
Manually Operated Switches
Switch that changes over when actuated and changes back immediately when released.   In FluidSIM switches can be actuated permanently (locked) when continuing to hold down the mouse button and pushing the Shift key. This permanent actuation is released by a simple click on the component.  
Related Topics  Detent switch (changeover) p2_2_7_6   Simultaneous Actuation of Several Components 39   
Pushbutton (changeover)
Pushbutton (changeover)
Component library
Electrical Components

p2_2_7_4.ct
Component library < Electrical Components < Manually Operated Switches < Detent switch (break)
Component library
Manually Operated Switches
Switch that opens and locks when actuated.  
Related Topics  Pushbutton (break) p2_2_7_1   Simultaneous Actuation of Several Components 39   
Detent switch (break)
Detent switch (break)
Component library
Electrical Components

p2_2_7_5.ct
Component library < Electrical Components < Manually Operated Switches < Detent switch (make)
Component library
Manually Operated Switches
Switch that closes and locks when actuated.  
Related Topics  Pushbutton (make) p2_2_7_2   Simultaneous Actuation of Several Components 39   
Detent switch (make)
Detent switch (make)
Component library
Electrical Components

p2_2_7_6.ct
Component library < Electrical Components < Manually Operated Switches < Detent switch (changeover)
Component library
Manually Operated Switches
Switch that changes over and locks when actuated.  
Related Topics  Pushbutton (changeover) p2_2_7_3   Simultaneous Actuation of Several Components 39   
Detent switch (changeover)
Detent switch (changeover)
Component library
Electrical Components

p2_2_8.ct
Component library < Electrical Components < Pressure Switches
Component library
Component library
Electrical Components
Pressure Switches
Pressure Switches
Pressure switch (break)
Pressure switch (make)
Pressure switch (changeover)
Pressure switch

p2_2_8_1.ct
Component library < Electrical Components < Pressure Switches < Pressure switch (break)
Component library
Pressure Switches
Switch that opens when the preset switching pressure of the hydraulic pressure switch p2_1_7_1 is exceeded. Pressure switches are created by using a general break switch p2_2_4_1 and setting a label.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Pressure switch (break)
Pressure switch (break)
Component library
Electrical Components

p2_2_8_2.ct
Component library < Electrical Components < Pressure Switches < Pressure switch (make)
Component library
Pressure Switches
The switch closes when the preset switching pressure of the hydraulic pressure switch p2_1_7_1 is exceeded. Pressure switches are created by using a general make switch p2_2_4_2 and setting a label.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Pressure switch (make)
Pressure switch (make)
Component library
Electrical Components

p2_2_8_3.ct
Component library < Electrical Components < Pressure Switches < Pressure switch (changeover)
Component library
Pressure Switches
The switch changes over when the preset switching pressure of the hydraulic pressure switch p2_1_7_1 is exceeded. Pressure switches are created by using a general changeover switch p2_2_4_3 and setting a label.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Pressure switch (changeover)
Pressure switch (changeover)
Component library
Electrical Components

p2_2_8_4.ct
Component library < Electrical Components < Pressure Switches < Pressure switch
Component library
Pressure Switches
The switch relays an electrical signal when the preset switching pressure at the hydraulic pressure switch p2_1_7_1 is exceeded.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Pressure switch
Pressure switch
Component library
Electrical Components

p2_2_9.ct
Component library < Electrical Components < Proximity Switches
Component library
Component library
Electrical Components
Proximity Switches
Proximity Switches
Magnetic proximity switch
Inductive proximity switch
Capacitive proximity switch
Optical proximity switch

p2_2_9_1.ct
Component library < Electrical Components < Proximity Switches < Magnetic proximity switch
Component library
Proximity Switches
Switch that closes when a solenoid is brought near by.   In the Simulation Mode the proximity switch can also be actuated by clicking 473 on it.  
Related Topics  Inductive proximity switch p2_2_9_2   Capacitive proximity switch p2_2_9_3   Optical proximity switch p2_2_9_4   Coupling Hydraulics, Electrics and Mechanics 49   
Magnetic proximity switch
Magnetic proximity switch
Component library
Electrical Components

p2_2_9_2.ct
Component library < Electrical Components < Proximity Switches < Inductive proximity switch
Component library
Proximity Switches
Switch that closes when the induced electro-magnetic field is changed.   In the Simulation Mode the proximity switch can also be actuated by clicking 473 on it.  
Related Topics  Magnetic proximity switch p2_2_9_1   Capacitive proximity switch p2_2_9_3   Optical proximity switch p2_2_9_4   Coupling Hydraulics, Electrics and Mechanics 49   
Inductive proximity switch
Inductive proximity switch
Component library
Electrical Components

p2_2_9_3.ct
Component library < Electrical Components < Proximity Switches < Capacitive proximity switch
Component library
Proximity Switches
Switch that closes when its electrostatic field is changed.   In the Simulation Mode the proximity switch can also be actuated by clicking 473 on it.  
Related Topics  Magnetic proximity switch p2_2_9_1   Inductive proximity switch p2_2_9_2   Optical proximity switch p2_2_9_4   Coupling Hydraulics, Electrics and Mechanics 49   
Capacitive proximity switch
Capacitive proximity switch
Component library
Electrical Components

p2_2_9_4.ct
Component library < Electrical Components < Proximity Switches < Optical proximity switch
Component library
Proximity Switches
Switch that closes when the light barrier is interrupted.   In the Simulation Mode the proximity switch can also be actuated by clicking 473 on it.  
Related Topics  Magnetic proximity switch p2_2_9_1   Inductive proximity switch p2_2_9_2   Capacitive proximity switch p2_2_9_3   Coupling Hydraulics, Electrics and Mechanics 49   
Optical proximity switch
Optical proximity switch
Component library
Electrical Components

p2_3.ct
Component library < Electrical Components (American Standard)
Component library
Electrical Components (American Standard)
Component library
Electrical Components (American Standard)
Power Supply
General Switches
Delay Switches
Limit Switches
Manually Operated Switches
Pressure Switches
Relays

p2_3_1.ct
Component library < Electrical Components (American Standard) < Power Supply
Component library
Component library
Electrical Components (American Standard)
Power Supply
Power Supply
Electrical connection 0V (ladder)
Electrical connection 24V (ladder)

p2_3_1_1.ct
Component library < Electrical Components (American Standard) < Power Supply < Electrical connection 0V (ladder)
Component library
Power Supply
0V connection of the power supply.  
Related Topic  Electrical connection 24V (ladder) p2_3_1_2   
Electrical connection 0V (ladder)
Electrical connection 0V (ladder)
Component library
Electrical Components (American Standard)

p2_3_1_2.ct
Component library < Electrical Components (American Standard) < Power Supply < Electrical connection 24V (ladder)
Component library
Power Supply
24V connection of the power supply.  
Related Topic  Electrical connection 0V (ladder) p2_3_1_1   
Electrical connection 24V (ladder)
Electrical connection 24V (ladder)
Component library
Electrical Components (American Standard)

p2_3_2.ct
Component library < Electrical Components (American Standard) < General Switches
Component library
Component library
Electrical Components (American Standard)
General Switches
General Switches
Break switch (ladder)
Make switch (ladder)

p2_3_2_1.ct
Component library < Electrical Components (American Standard) < General Switches < Break switch (ladder)
Component library
General Switches
General break switch that is tailored depending on the type of component that actuates it.  For example, if the break switch is linked via a label to a switch-off delay relay p2_3_7_3, the break switch changes to a switch-off delay break switch p2_3_3_3 in the circuit diagram.  
Related Topics  Relay (ladder) p2_3_7_1   Break switch (switch-on delayed, ladder) p2_3_3_1   Break switch (switch-off delayed, ladder) p2_3_3_3   Limit switch (break, ladder) p2_3_4_1   Pressure switch (break, ladder) p2_3_6_1   Coupling Hydraulics, Electrics and Mechanics 49   
Break switch (ladder)
Break switch (ladder)
Component library
Electrical Components (American Standard)

p2_3_2_2.ct
Component library < Electrical Components (American Standard) < General Switches < Make switch (ladder)
Component library
General Switches
General make switch that is tailored according to the component that actuates it.  For example, if the make switch is linked via a label to a switch-on delayed relay p2_3_7_2, the make switch changes to a switch-on delayed make switch p2_3_3_2 in the circuit diagram.  
Related Topics  Relay (ladder) p2_3_7_1   Make switch (switch-on delayed, ladder) p2_3_3_2   Make switch (switch-off delayed, ladder) p2_3_3_4   Limit switch (make, ladder) p2_3_4_2   Pressure switch (make, ladder) p2_3_6_2   Coupling Hydraulics, Electrics and Mechanics 49   
Make switch (ladder)
Make switch (ladder)
Component library
Electrical Components (American Standard)

p2_3_3.ct
Component library < Electrical Components (American Standard) < Delay Switches
Component library
Component library
Electrical Components (American Standard)
Delay Switches
Delay Switches
Break switch (switch-on delayed, ladder)
Make switch (switch-on delayed, ladder)
Break switch (switch-off delayed, ladder)
Make switch (switch-off delayed, ladder)

p2_3_3_1.ct
Component library < Electrical Components (American Standard) < Delay Switches < Break switch (switch-on delayed, ladder)
Component library
Delay Switches
Switch with delayed opening after pickup. Switch-on delayed break switches are created by using a general break switch p2_3_2_1 and setting a label.  
Related Topics  Relay with switch-on delay (ladder) p2_3_7_2   Break switch (switch-off delayed, ladder) p2_3_3_3   Coupling Hydraulics, Electrics and Mechanics 49   
Break switch (switch-on delayed, ladder)
Break switch (switch-on delayed, ladder)
Component library
Electrical Components (American Standard)

p2_3_3_2.ct
Component library < Electrical Components (American Standard) < Delay Switches < Make switch (switch-on delayed, ladder)
Component library
Delay Switches
Switch with delayed closing after pickup. Switch-on delayed make switches are created by using a general make switch p2_3_2_2 and setting a label.  
Related Topics  Relay with switch-on delay (ladder) p2_3_7_2   Make switch (switch-off delayed, ladder) p2_3_3_4   Coupling Hydraulics, Electrics and Mechanics 49   
Make switch (switch-on delayed, ladder)
Make switch (switch-on delayed, ladder)
Component library
Electrical Components (American Standard)

p2_3_3_3.ct
Component library < Electrical Components (American Standard) < Delay Switches < Break switch (switch-off delayed, ladder)
Component library
Delay Switches
Switch with delayed closing after dropout. Switch-off delayed break switches are created by using a general break switch p2_3_2_1 and setting a label.  
Related Topics  Relay with switch-off delay (ladder) p2_3_7_3   Break switch (switch-on delayed, ladder) p2_3_3_1   Coupling Hydraulics, Electrics and Mechanics 49   
Break switch (switch-off delayed, ladder)
Break switch (switch-off delayed, ladder)
Component library
Electrical Components (American Standard)

p2_3_3_4.ct
Component library < Electrical Components (American Standard) < Delay Switches < Make switch (switch-off delayed, ladder)
Component library
Delay Switches
Switch with delayed opening after dropout. Switch-off delayed make switches are created by using a general make switch p2_3_2_2 and setting a label.  
Related Topics  Relay with switch-off delay (ladder) p2_3_7_3   Make switch (switch-on delayed, ladder) p2_3_3_2   Coupling Hydraulics, Electrics and Mechanics 49   
Make switch (switch-off delayed, ladder)
Make switch (switch-off delayed, ladder)
Component library
Electrical Components (American Standard)

p2_3_4.ct
Component library < Electrical Components (American Standard) < Limit Switches
Component library
Component library
Electrical Components (American Standard)
Limit Switches
Limit Switches
Limit switch (break, ladder)
Limit switch (make, ladder)

p2_3_4_1.ct
Component library < Electrical Components (American Standard) < Limit Switches < Limit switch (break, ladder)
Component library
Limit Switches
Switch that is opened by a cam attached to the cylinder rod. The switch closes immediately when the cam has passed the switch. Limit switches are created by using a general break switch p2_3_2_1 and setting a label.  
Related Topics  Switches at Cylinders 52   Distance rule p2_6_1_7   
Limit switch (break, ladder)
Limit switch (break, ladder)
Component library
Electrical Components (American Standard)

p2_3_4_2.ct
Component library < Electrical Components (American Standard) < Limit Switches < Limit switch (make, ladder)
Component library
Limit Switches
Switch that is closed by a cam attached to the cylinder rod. The switch opens immediately when the cam has passed the switch. Limit switches are created by using a general make switch p2_3_2_2 and setting a label.  
Related Topics  Switches at Cylinders 52   Distance rule p2_6_1_7   
Limit switch (make, ladder)
Limit switch (make, ladder)
Component library
Electrical Components (American Standard)

p2_3_5.ct
Component library < Electrical Components (American Standard) < Manually Operated Switches
Component library
Component library
Electrical Components (American Standard)
Manually Operated Switches
Manually Operated Switches
Pushbutton (break, ladder)
Pushbutton (make, ladder)
Pushbutton (changeover, ladder)

p2_3_5_1.ct
Component library < Electrical Components (American Standard) < Manually Operated Switches < Pushbutton (break, ladder)
Component library
Manually Operated Switches
Switch that opens when actuated and closes immediately when released.   In FluidSIM switches can be actuated permanently (locked) when continuing to hold down the mouse button and pushing the Shift key. This permanent actuation is released by a simple click on the component.  
Related Topic  Simultaneous Actuation of Several Components 39   
Pushbutton (break, ladder)
Pushbutton (break, ladder)
Component library
Electrical Components (American Standard)

p2_3_5_2.ct
Component library < Electrical Components (American Standard) < Manually Operated Switches < Pushbutton (make, ladder)
Component library
Manually Operated Switches
Switch that closes when actuated and opens immediately when released.   In FluidSIM switches can be actuated permanently (locked) when continuing to hold down the mouse button and pushing the Shift key. This permanent actuation is released by a simple click on the component.  
Related Topic  Simultaneous Actuation of Several Components 39   
Pushbutton (make, ladder)
Pushbutton (make, ladder)
Component library
Electrical Components (American Standard)

p2_3_5_3.ct
Component library < Electrical Components (American Standard) < Manually Operated Switches < Pushbutton (changeover, ladder)
Component library
Manually Operated Switches
Switch that changes over when actuated and changes back immediately when released.   In FluidSIM switches can be actuated permanently (locked) when continuing to hold down the mouse button and pushing the Shift key. This permanent actuation is released by a simple click on the component.  
Related Topic  Simultaneous Actuation of Several Components 39   
Pushbutton (changeover, ladder)
Pushbutton (changeover, ladder)
Component library
Electrical Components (American Standard)

p2_3_6.ct
Component library < Electrical Components (American Standard) < Pressure Switches
Component library
Component library
Electrical Components (American Standard)
Pressure Switches
Pressure Switches
Pressure switch (break, ladder)
Pressure switch (make, ladder)

p2_3_6_1.ct
Component library < Electrical Components (American Standard) < Pressure Switches < Pressure switch (break, ladder)
Component library
Pressure Switches
Switch that opens when the preset switching pressure of the hydraulic pressure switch p2_1_7_1 is exceeded. Pressure switches are created by using a general break switch p2_3_2_1 and setting a label.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Pressure switch (break, ladder)
Pressure switch (break, ladder)
Component library
Electrical Components (American Standard)

p2_3_6_2.ct
Component library < Electrical Components (American Standard) < Pressure Switches < Pressure switch (make, ladder)
Component library
Pressure Switches
The switch closes when the preset switching pressure of the hydraulic pressure switch p2_1_7_1 is exceeded. Pressure switches are created by using a general make switch p2_3_2_2 and setting a label.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Pressure switch (make, ladder)
Pressure switch (make, ladder)
Component library
Electrical Components (American Standard)

p2_3_7.ct
Component library < Electrical Components (American Standard) < Relays
Component library
Component library
Electrical Components (American Standard)
Relays
Relays
Relay (ladder)
Relay with switch-on delay (ladder)
Relay with switch-off delay (ladder)

p2_3_7_1.ct
Component library < Electrical Components (American Standard) < Relays < Relay (ladder)
Component library
Relays
The relay picks up immediately when current is supplied and drops out immediately when current is removed.  
Related Topics  Break switch (ladder) p2_3_2_1   Coupling Hydraulics, Electrics and Mechanics 49   
Relay (ladder)
Relay (ladder)
Component library
Electrical Components (American Standard)

p2_3_7_2.ct
Component library < Electrical Components (American Standard) < Relays < Relay with switch-on delay (ladder)
Component library
Relays
The relay picks up after a preset time when current is supplied and drops out immediately when current is removed.  Adjustable parameters  	Delay time:	0 ... 100 s	(5)  
Related Topics  Break switch (switch-on delayed, ladder) p2_3_3_1   Make switch (switch-on delayed, ladder) p2_3_3_2   Coupling Hydraulics, Electrics and Mechanics 49   
Relay with switch-on delay (ladder)
Relay with switch-on delay (ladder)
Component library
Electrical Components (American Standard)

p2_3_7_3.ct
Component library < Electrical Components (American Standard) < Relays < Relay with switch-off delay (ladder)
Component library
Relays
The relay picks up immediately when current is supplied and drops out after a preset time when current is removed.  Adjustable parameters  	Delay time:	0 ... 100 s	(5)  
Related Topics  Break switch (switch-off delayed, ladder) p2_3_3_3   Make switch (switch-off delayed, ladder) p2_3_3_4   Coupling Hydraulics, Electrics and Mechanics 49   
Relay with switch-off delay (ladder)
Relay with switch-off delay (ladder)
Component library
Electrical Components (American Standard)

p2_4.ct
Component library < Digital Components
Component library
Digital Components
Component library
Digital Components
Constants and Connectors
Basic Functions
Special Functions

p2_4_1.ct
Component library < Digital Components < Constants and Connectors
Component library
Component library
Digital Components
Constants and Connectors
Constants and Connectors
Digital input
Digital output
Memory bits
Logic level HI
Logic level LO
Connection (digital)
Line (digital)
T-junction (digital)

p2_4_1_1.ct
Component library < Digital Components < Constants and Connectors < Digital input
Component library
Constants and Connectors
Digital inputs are designated with an “I”. In FluidSIM digital components can be used inside and outside a digital module.   If a digital input is used inside a digital module, you can determine the input connector of the digital module in question with which the digital input shall be linked by allocating a number “I1” to “I16”. If there is an analog signal of more than 10V at the chosen input of the digital module, the digital input is set to “Hi”.   If a digital input is used outside a digital module, there is an additional analog electrical connection at the digital input. If there is an analog signal of more than 10V at this connection, the digital input is set to “Hi”.   As an alternative you can click on the digital input with the left mouse button in order to set it to “Hi”. Another click resets the value to “Lo”.  
Related Topics  Digital module p2_4_3_1   Digital output p2_4_1_2   
Digital input
Digital input
Component library
Digital Components

p2_4_1_2.ct
Component library < Digital Components < Constants and Connectors < Digital output
Component library
Constants and Connectors
Digital outputs are designated with an “Q”. The output connects a digital signal through from its input to its output. In FluidSIM digital components can be used inside and outside a digital module.   If a digital output is used inside a digital module, you can determine the output connector of the digital module in question with which the digital output shall be linked by allocating a number “Q1” to “Q16”. If the status of the digital output is “Hi”, a potential of 24V is set at the corresponding output connector of the digital module.   If a digital output is used outside a digital module, there is an additional analog electrical connection at the digital output. If the status of the digital output is “Hi”, a potential of 24 V is set a this connection.  
Related Topics  Digital module p2_4_3_1   Digital input p2_4_1_1   Memory bits p2_4_1_3   
Digital output
Digital output
Component library
Digital Components

p2_4_1_3.ct
Component library < Digital Components < Constants and Connectors < Memory bits
Component library
Constants and Connectors
Memory bits are designated with a “M”. Memory bits are virtual outputs, with a value at their output analog to that at their input.   When the simulation start is activated, you can define by using the property dialog box if the output Q shall be set to “Lo” or to “Hi”, independent on the input value. After the simulation start the value at the output is set to the value of the input.  
Related Topic  Digital output p2_4_1_2   
Memory bits
Memory bits
Component library
Digital Components

p2_4_1_4.ct
Component library < Digital Components < Constants and Connectors < Logic level HI
Component library
Constants and Connectors
At the output Q you have the logic level “Hi”.  
Related Topic  Logic level LO p2_4_1_5   
Logic level HI
Logic level HI
Component library
Digital Components

p2_4_1_5.ct
Component library < Digital Components < Constants and Connectors < Logic level LO
Component library
Constants and Connectors
At the output Q you have the logic level “Lo”.  
Related Topic  Logic level HI p2_4_1_4   
Logic level LO
Logic level LO
Component library
Digital Components

p2_4_1_6.ct
Component library < Digital Components < Constants and Connectors < Connection (digital)
Component library
Constants and Connectors
An digital connection is a place where a digital line can be attached to. To simplify the line drawing process, a connection appears as a small circle in Edit Mode.   Note that at each digital connection its level “Lo” / “Hi” can be displayed.  
Related Topics  Line (digital) p2_4_1_7   T-junction (digital) p2_4_1_8   Creating new Circuit Diagrams 19   Insertion of T-connections 43   Drawing Errors 452   Displaying Quantity Values 45   
Connection (digital)
Connection (digital)
Component library
Digital Components

p2_4_1_7.ct
Component library < Digital Components < Constants and Connectors < Line (digital)
Component library
Constants and Connectors
A digital line links two digital connections. Note that a digital connection may be a simple digital connection p2_4_1_6 or a T-junction p2_4_1_8.  
Related Topic  Creating new Circuit Diagrams 19   
Line (digital)
Line (digital)
Component library
Digital Components

p2_4_1_8.ct
Component library < Digital Components < Constants and Connectors < T-junction (digital)
Component library
Constants and Connectors
A T-junction joins up to four digital lines p2_4_1_7, thus having a single digital level. Note that T-junctions are introduced automatically by FluidSIM when dropping the line drawing cursor onto another line in Edit Mode.  
Related Topics  Connection (digital) p2_4_1_6   Creating new Circuit Diagrams 19   
T-junction (digital)
T-junction (digital)
Component library
Digital Components

p2_4_2.ct
Component library < Digital Components < Basic Functions
Component library
Component library
Digital Components
Basic Functions
Basic Functions
AND
Edge-triggered AND
NAND (AND not)
NAND With Edge Evaluation
NOR (OR not)
XOR (exclusive OR)
NOT (Negation, Inverter)

p2_4_2_1.ct
Component library < Digital Components < Basic Functions < AND
Component library
Basic Functions
The output Q of the AND is only “Hi” when all inputs are “Hi”, that is, if they are closed. If an input pin of this module is not connected, its status is automatically “Hi”.  
Related Topic  Edge-triggered AND p2_4_2_2   
AND
AND
Component library
Digital Components

p2_4_2_2.ct
Component library < Digital Components < Basic Functions < Edge-triggered AND
Component library
Basic Functions
The output Q of the edge-triggered AND is only “Hi” when all inputs are “Hi” and if at least one input was “Lo” in the previous cycle. If an input pin of this block is not connected, its status is automatically “Hi”.  
Related Topic  AND p2_4_2_1   
Edge-triggered AND
Edge-triggered AND
Component library
Digital Components

p2_4_2_3.ct
Component library < Digital Components < Basic Functions < NAND (AND not)
Component library
Basic Functions
The output Q of the NAND is only “Lo”, when all inputs are “Hi”, that is, if they are closed. If an input pin of this block is not connected, its status is automatically “Hi”.  
Related Topic  NAND With Edge Evaluation p2_4_2_4   
NAND (AND not)
NAND (AND not)
Component library
Digital Components

p2_4_2_4.ct
Component library < Digital Components < Basic Functions < NAND With Edge Evaluation
Component library
Basic Functions
The output Q of the NAND with edge evaluation is only “Hi”, if at least one input is “Lo” and if all inputs were “Hi” in the previous cycle. If an input pin of this block is not connected, its status is automatically “Hi”.  
Related Topic  NAND (AND not) p2_4_2_3   
NAND With Edge Evaluation
NAND With Edge Evaluation
Component library
Digital Components

p2_4_2_5.ct
Component library < Digital Components < Basic Functions < OR
Component library
Basic Functions
The output Q of the OR is only “Hi”, if at least one input is “Hi”, that is, if it is closed. If an input pin of this block is not connected, its status is automatically “Lo”.  
Related Topics  NOR (OR not) p2_4_2_6   XOR (exclusive OR) p2_4_2_7   
Component library
Digital Components

p2_4_2_6.ct
Component library < Digital Components < Basic Functions < NOR (OR not)
Component library
Basic Functions
The output Q of the NOR is only “Hi” when all inputs are “Lo”, that is, if they are switched off. As soon as any input is switched on (status “Hi”), the output of the NOR is set to “Lo”. If an input pin of this block is not connected, its status is automatically “Lo”.  
Related Topics  OR p2_4_2_5   XOR (exclusive OR) p2_4_2_7   
NOR (OR not)
NOR (OR not)
Component library
Digital Components

p2_4_2_7.ct
Component library < Digital Components < Basic Functions < XOR (exclusive OR)
Component library
Basic Functions
The output Q of the XOR is “Hi”, if the inputs are nonequivalent. If an input pin of this block is not connected, its status is automatically “Lo”.  
Related Topics  OR p2_4_2_5   NOR (OR not) p2_4_2_6   
XOR (exclusive OR)
XOR (exclusive OR)
Component library
Digital Components

p2_4_2_8.ct
Component library < Digital Components < Basic Functions < NOT (Negation, Inverter)
Component library
Basic Functions
The output Q is “Hi” if the input is “Lo”. The NOT block is an input status inverter.  
NOT (Negation, Inverter)
NOT (Negation, Inverter)
Component library
Digital Components

p2_4_3.ct
Component library < Digital Components < Special Functions
Component library
Component library
Digital Components
Special Functions
Special Functions
Digital module
On delay
Off delay
On/Off delay
Retentive On delay
Latching Relay
Pulse Relay
Wiping Relay - Pulse Output
Edge-triggered Wiping Relay
Timer Switch
Up/Down Counter
Symmetric Clock Generator
Asynchronous Pulse Generator
Frequency Threshold Trigger

p2_4_3_1.ct
Component library < Digital Components < Special Functions < Digital module
Component library
Special Functions
The digital module is used for a compact embedding of a digital switching circuit into a electrohydraulic circuit. The digital module offers 8 (16) electrical inputs and outputs, which transfer their states to its digital switching circuit in the inner part. Therefore the digital switching circuit does not need much space in the electrohydraulic circuit for the display of the digital module as a rectangle with a total number of 18 (34) connections. By making a double-click with the left mouse button on the digital module you come to the digital circuit in the inner part of the module. A new window opens. It shows the digital circuit and can be handled in the usual way. The standard configuration in the inner part of a new inserted digital module is a row with 8 (16) inputs and 8 (16) outputs each. They correspond to the inputs and outputs of the module in the electrohydraulic circuit. In order to be able to test the digital circuit during the set-up, it can be simulated separated from the electrohydraulic circuit. As soon as the processing window of the digital module is closed or the original circuit window is put into the foreground, the previously effected changes in the digital circuit are automatically adopted into the digital module of the electrohydraulic circuit. Inside the digital module only digital components can be inserted. Furthermore, an encapsulating of additional digital modules inside a module is not possible. However, you can use several digital modules in one electrohydraulic circuit. Please note that the digital circuit inside a digital module only works correctly if corresponding potentials are set at the electrical power supply units of the module (+24 V) and (0 V).  
Related Topics  Digital input p2_4_1_1   Digital output p2_4_1_2   
Digital module
Digital module
Component library
Digital Components

p2_4_3_10.ct
Component library < Digital Components < Special Functions < Timer Switch
Component library
Special Functions
With the timer switch you can create timer switches referring to days, weeks and years. Upon reach of the specified on-transition time, the output Q of the timer switch is set to “Hi” and upon reach of the specified off-transition time to “Lo”. If you have chosen the option “repeat all”, the on and off transition is repeated each time according to the specified repetition time.  Adjustable parameters  	On time:	0 ... 1000 s	(10)  	Off time:	0,1 ... 1000 s	(30)  	Repeat every:	0,1 ... 1000 s	(60)  
Related Topics  On delay p2_4_3_2   Off delay p2_4_3_3   On/Off delay p2_4_3_4   Retentive On delay p2_4_3_5   
Timer Switch
Timer Switch
Component library
Digital Components

p2_4_3_11.ct
Component library < Digital Components < Special Functions < Up/Down Counter
Component library
Special Functions
Depending on the configuration of the input Dir, an internal value is counted up or down through an input pulse. The output is set when the configured count value is reached.   With every status change at the input Cnt from “Lo” to “Hi”, the internal counter is increased (Dir = “Lo”) or decreased (Dir = “Hi”) by one unit. If the internal counter is equal or larger compared to the specified value, the output Q is set to “Hi”.   You can use the reset input R to reset the internal count value and the output to “Lo”. As long as R=“Hi”, also the output is “Lo” and the pulses at input Cnt are not counted.  Adjustable parameters  	Counter:	0 ... 9999 pulses	(5)  
Up/Down Counter
Up/Down Counter
Component library
Digital Components

p2_4_3_12.ct
Component library < Digital Components < Special Functions < Symmetric Clock Generator
Component library
Special Functions
A timing signal with a configurable period is given at the output. Via the duration of the pulses you can determine the length of the on and off times. Via the input En (for Enable) you can switch on the clock generator, that is, the clock generator sets the output to “Hi” for the duration of the pulse, subsequent the output to “Lo” for the duration of the pulse and so on, until the input status is “Lo” again.  Adjustable parameters  	Impulse time:	0,1 ... 100 s	(0,5)  
Symmetric Clock Generator
Symmetric Clock Generator
Component library
Digital Components

p2_4_3_13.ct
Component library < Digital Components < Special Functions < Asynchronous Pulse Generator
Component library
Special Functions
The pulse profile of the output can be changed via the configurable pulse duration and pulse pause duration.   It is possible to invert the output with input INV. The input INV only negates the output, if the block is enabled via EN.  Adjustable parameters  	Impulse time:	0,1 ... 100 s	(3)  	Impulse pause time:	0,1 ... 100 s	(1)  
Related Topic  Symmetric Clock Generator p2_4_3_12   
Asynchronous Pulse Generator
Asynchronous Pulse Generator
Component library
Digital Components

p2_4_3_14.ct
Component library < Digital Components < Special Functions < Frequency Threshold Trigger
Component library
Special Functions
The output is switched on and off depending on two frequencies which can be specified.   The threshold trigger measures the signals at input Fre. The pulses are captured across a measuring interval which can be specified. If the frequency measured within the measuring interval higher than the input frequency, the output Q is switched to “Hi”. Q is switched again to “Lo” when the measured frequency has reached the value of the output frequency or if it is lower.  Adjustable parameters  	On frequency:	0,1 ... 10 pulses/sec	(6)  	Off frequency:	0,1 ... 10 pulses/sec	(2)  	Time interval:	0,1 ... 100 s	(5)  
Frequency Threshold Trigger
Frequency Threshold Trigger
Component library
Digital Components

p2_4_3_2.ct
Component library < Digital Components < Special Functions < On delay
Component library
Special Functions
An output with on delay is not switched on until a specified time has expired.   When the status of input Trg changes from “Lo” to “Hi”, the on delay time starts.   If the status of input Trg is “Hi” at least for the duration of the configured time, the output Q is set to “Hi” on expiration of this time. The output follows the input with on delay. The time is reset, when the status of the input changes again to “Lo” before the time has expired. The output is reset to “Lo”, when the status at the input is “Lo”.  Adjustable parameters  	On delay time:	0 ... 100 s	(3)  
Related Topics  Off delay p2_4_3_3   On/Off delay p2_4_3_4   Retentive On delay p2_4_3_5   Timer Switch p2_4_3_10   
On delay
On delay
Component library
Digital Components

p2_4_3_3.ct
Component library < Digital Components < Special Functions < Off delay
Component library
Special Functions
The output is not reset until a configured time has expired.   When the input status turns to “Hi”, the output Q is switched instantaneously to “Hi”. If the status at input Trg changes from “Hi” to “Lo”, the off delay starts. After expiration of the configured time, the output is reset to “Lo” (off delay). When the input Trg is switched on and off again, the off delay restarts. The input R (Reset) is used to reset the delay time and the output before the configured time has expired.  Adjustable parameters  	Off delay time:	0 ... 100 s	(3)  
Related Topics  On delay p2_4_3_2   On/Off delay p2_4_3_4   Retentive On delay p2_4_3_5   Timer Switch p2_4_3_10   
Off delay
Off delay
Component library
Digital Components

p2_4_3_4.ct
Component library < Digital Components < Special Functions < On/Off delay
Component library
Special Functions
An output with on/off delay is switched on after a specified time and is reset on expiration of a second specified time.   As soon as the status at input Trg changes from “Lo” to “Hi”, the configured on delay time starts. If the status at input Trg remains “Hi” at least for the duration of the configured time, the output Q is set to “Hi” on expiration of the on delay time (the output follows the input on delayed). If the status at input Trg changes again to “Lo”, before the configured on delay time has expired, the time is reset. When the status at input returns to “Lo”, the configured off delay time starts.   If the status at the input remains “Lo” at least for the duration of the configured off delay time, the output is set to “Lo” on expiration of that time (the output follows the input off delayed). If the status at the input returns to “Hi” before this time has expired, the time is reset.  Adjustable parameters  	On delay time:	0 ... 100 s	(3)  	Off delay time:	0 ... 100 s	(3)  
Related Topics  On delay p2_4_3_2   Off delay p2_4_3_3   Retentive On delay p2_4_3_5   Timer Switch p2_4_3_10   
On/Off delay
On/Off delay
Component library
Digital Components

p2_4_3_5.ct
Component library < Digital Components < Special Functions < Retentive On delay
Component library
Special Functions
A specified time starts after an input pulse. The output is set on expiration of this time.   As soon as the status at the input Trg changes from “Lo” to “Hi”, the specified time starts. After expiration on the configured time, the output Q is set to “Hi”. Further switching actions at input Trg have no influence on the running time. The output and the time are only reset to “Lo” when the status at input R is “Hi”.  Adjustable parameters  	On delay time:	0 ... 100 s	(3)  
Related Topics  On delay p2_4_3_2   Off delay p2_4_3_3   On/Off delay p2_4_3_4   Timer Switch p2_4_3_10   
Retentive On delay
Retentive On delay
Component library
Digital Components

p2_4_3_6.ct
Component library < Digital Components < Special Functions < Latching Relay
Component library
Special Functions
Input S sets output Q. Another input R resets the output Q.   A latching relay is a simple logic memory. The output value depends on the input states and on the previous output status.  
Latching Relay
Latching Relay
Component library
Digital Components

p2_4_3_7.ct
Component library < Digital Components < Special Functions < Pulse Relay
Component library
Special Functions
A short one-shot at the input is used to set and reset the output.   Output Q status is toggled at every “Lo” to “Hi” transition of the status at input Trg, that is, the output is switched on or off. Use input R to reset the pulse relay to initial state, that is, the output is set to “Lo”.  
Pulse Relay
Pulse Relay
Component library
Digital Components

p2_4_3_8.ct
Component library < Digital Components < Special Functions < Wiping Relay - Pulse Output
Component library
Special Functions
An input signal generates a signal of specified length at the output.   The output status is switched to “Hi” after the input Trg is set to “Hi”. The configured time is started at the same time and the output remains set. After expiration of the configured time, the output is reset to the status “Lo” (pulse output). If the input status changes from “Hi” to “Lo” before the specified time has expired, also the output follows immediately with a with a “Hi” to “Lo” transition.  Adjustable parameters  	Delay time:	0 ... 100 s	(3)  
Related Topic  Edge-triggered Wiping Relay p2_4_3_9   
Wiping Relay - Pulse Output
Wiping Relay - Pulse Output
Component library
Digital Components

p2_4_3_9.ct
Component library < Digital Components < Special Functions < Edge-triggered Wiping Relay
Component library
Special Functions
An input signal generates a signal of specified length at the output (retriggering).   The output status is switched to “Hi” after the input Trg is set to “Hi”. The configured time is started at the same time. After expiration of the configured time, the output Q status is reset to “Lo” (pulse output). If the input status changes again from “Lo” to “Hi” (retriggering), before the specified time has expired, the time is reset and the output remains switched on.  Adjustable parameters  	Delay time:	0 ... 100 s	(3)  
Related Topic  Wiping Relay - Pulse Output p2_4_3_8   
Edge-triggered Wiping Relay
Edge-triggered Wiping Relay
Component library
Digital Components

p2_5.ct
Component library < GRAFCET Elements
Component library
GRAFCET Elements
Component library
GRAFCET Elements
GRAFCET

p2_5_1.ct
Component library < GRAFCET Elements < GRAFCET
Component library
Component library
GRAFCET Elements
GRAFCET
GRAFCET
Step
Transition
Action
Synchronization
Partial GRAFCET
GRAFCET-I/O

p2_5_1_1.ct
Component library < GRAFCET Elements < GRAFCET < Step
Component library
GRAFCET
The name of a step may contain the following characters: “0-9”, “a-z”, “A-Z” and the underscore “_”.   You can select from the following seven different step types: simple step, initial step, macro-step, macro input, macro output, enclosing step and initial enclosing step.   Furthermore, you can give the step an activation link.   
Related Topics  Admissible characters for steps and variables 29835   Transition p2_5_1_2   Action p2_5_1_3   Synchronization p2_5_1_4   Partial GRAFCET p2_5_1_5   
Step
Step
Component library
GRAFCET Elements

p2_5_1_2.ct
Component library < GRAFCET Elements < GRAFCET < Transition
Component library
GRAFCET
You can give a transition a name, which is shown to the left of the transition in brackets.   Entering a transition condition is supported by buttons for special symbols (AND, OR, NOT, falling edge, rising edge, delay). Via Variable... you can select an existing GRAFCET variable from a list. Alternatively to the formula, you can show a descriptive text. To do this, you have to select the option “Display description instead of formula”.   In the “Connection ID/target information” field, you can enter a step that links to the transition's output without having to draw a connecting line. You can select an existing step from a list.   
Related Topics  Variable names 29836   Functions and formula entry 29837   Target information 29840   Step p2_5_1_1   Synchronization p2_5_1_4   
Transition
Transition
Component library
GRAFCET Elements

p2_5_1_3.ct
Component library < GRAFCET Elements < GRAFCET < Action
Component library
GRAFCET
There are three types of action: assignations, allocations and compulsory commands.   For assignations and allocations, you can enter a variable or an output, whose value is changed by the action. The name of a variable may contain the following characters: “0-9”, “a-z”, “A-Z” and the underscore “_”.   For a “conditional action” or an “action on event”, you can enter a condition that has to be fulfilled before the action is executed. Entering a condition is supported by buttons for special symbols (AND, OR, NOT, falling edge, rising edge, delay). Via Variable... you can select an existing GRAFCET variable from a list. Alternatively to the formula, you can show a descriptive text. To do this, you have to select the option “Display description instead of formula”.   For an allocation (“action on activation”, “action on deactivation” and “action on event”), you can enter any term whose value is to be allocated to the action variable. Entering a term is supported by buttons for special symbols (AND, OR, NOT, falling edge, rising edge). Via Variable... you can select an existing GRAFCET variable from a list. Alternatively to the formula, you can show a descriptive text. To do this, you have to select the option “Display description instead of formula”.   For a “compulsory command”, you can enter the name of the partial GRAFCET directly or select an existing partial GRAFCET from a list. You can also enter the relevant steps directly or select them from a list of existing steps. You have to separate the step names with commas. You can select the special commands “*” and “INIT” using the relevant buttons.   
Related Topics  Variable names 29836   Functions and formula entry 29837   Compulsory commands 29843   Step p2_5_1_1   Transition p2_5_1_2   GRAFCET-I/O p2_5_1_6   
Action
Action
Component library
GRAFCET Elements

p2_5_1_4.ct
Component library < GRAFCET Elements < GRAFCET < Synchronization
Component library
GRAFCET
You can connect synchronizations like other FluidSIM components. However, they do not initially have any connections. You always have to draw connecting lines to a synchronization. The corresponding connections are then generated automatically.   
Related Topics  Synchronization 29831   Step p2_5_1_1   Transition p2_5_1_2   Partial GRAFCET p2_5_1_5   
Synchronization
Synchronization
Component library
GRAFCET Elements

p2_5_1_5.ct
Component library < GRAFCET Elements < GRAFCET < Partial GRAFCET
Component library
GRAFCET
If you want to allocate GRAFCET elements to a specific partial GRAFCET, place the partial GRAFCET frame over the relevant GRAFCET part and give it a name. The preceding “G” is not part of the name that you have to enter; it is added automatically by FluidSIM and shown at the bottom left of the partial GRAFCET frame. You can alter the size of the partial GRAFCET frame by dragging its edges with the mouse. For the partial GRAFCET to function correctly, it is important that all its elements are completely within the frame and that the frame does not overlap with any foreign elements or other frames.   
Related Topics  Partial GRAFCETs 29841   Enclosing step 29844   Compulsory commands 29843   Step p2_5_1_1   Transition p2_5_1_2   Action p2_5_1_3   Synchronization p2_5_1_4   
Partial GRAFCET
Partial GRAFCET
Component library
GRAFCET Elements

p2_5_1_6.ct
Component library < GRAFCET Elements < GRAFCET < GRAFCET-I/O
Component library
GRAFCET
The GRAFCET I/O component is used to link the GRAFCET variables with the electrical part of a circuit. You can enter eight GRAFCET input variables and eight GRAFCET output variables into the GRAFCET I/O component. The actions' variables serve as outputs. The inputs can be the allocations and conditions of actions and transitions.   If a potential is created as the input of the GRAFCET I/O component, the corresponding variable is set to “1”. If an output variable has a value other than “0”, a potential of 24V is created at the corresponding output of the GRAFCET I/O component.   
Related Topics  Access to labels of fluidic and electrical components 29848   Linking GRAFCET variables with the electrical part of FluidSIM 29826   Transition p2_5_1_2   Action p2_5_1_3   
GRAFCET-I/O
GRAFCET-I/O
Component library
GRAFCET Elements

p2_6.ct
Component library < Miscellaneous
Component library
Miscellaneous
Component library
Miscellaneous
Miscellaneous

p2_6_1.ct
Component library < Miscellaneous < Miscellaneous
Component library
Component library
Miscellaneous
Miscellaneous
Miscellaneous
Connection (mechanical)
Valve solenoid
Proportional valve solenoid, position controlled
Proportional amplifier, 1-channel
Proportional amplifier, 2-channel
Valve solenoid (ladder)
Distance rule
Status indicator
Cam switch
Text
State diagram
Terminal assignment diagram
Functional diagram editor
Parts list
Rectangle
Ellipse
Bitmap

p2_6_1_1.ct
Component library < Miscellaneous < Miscellaneous < Connection (mechanical)
Component library
Miscellaneous
A mechanical connection constitutes a place holder for the label of a valve solenoid. To simplify clicking, a mechanical connection appears as a small circle in Edit Mode.  
Related Topic  Coupling Hydraulics, Electrics and Mechanics 49   
Connection (mechanical)
Connection (mechanical)
Component library
Miscellaneous

p2_6_1_10.ct
Component library < Miscellaneous < Miscellaneous < Text
Component library
Miscellaneous
The concept of text components in FluidSIM gives the user a way in which to describe components in diagrams, assign identification texts, or to provide commentary on the diagram. The text and the appearance of text components can be customized to the user's liking.  
Related Topics  Text Components and Identifications 79   Displaying State Diagrams 47   Parts Lists 80   
Text
Text
Component library
Miscellaneous

p2_6_1_11.ct
Component library < Miscellaneous < Miscellaneous < State diagram
Component library
Miscellaneous
The state diagram records the state quantities of important components and depicts them graphically.  
Related Topic  Displaying State Diagrams 47   
State diagram
State diagram
Component library
Miscellaneous

p2_6_1_12.ct
Component library < Miscellaneous < Miscellaneous < Terminal assignment diagram
Component library
Miscellaneous
The terminal assignment diagram list automatically creates terminals in the electrical circuit and displays the allocation in a table.  
Related Topic  Terminal Assignment Diagrams 906   
Terminal assignment diagram
Terminal assignment diagram
Component library
Miscellaneous

p2_6_1_13.ct
Component library < Miscellaneous < Miscellaneous < Functional diagram editor
Component library
Miscellaneous
With the functional diagram editor, functional diagrams e.g. displacement-step diagrams can be created.  
Related Topic  Functional diagram editor 5988   
Functional diagram editor
Functional diagram editor
Component library
Miscellaneous

p2_6_1_14.ct
Component library < Miscellaneous < Miscellaneous < Parts list
Component library
Miscellaneous
The parts list component creates from the components of a circuit diagram a table, which contains for each component its designation and its description.  
Related Topic  Parts Lists 80   
Parts list
Parts list
Component library
Miscellaneous

p2_6_1_15.ct
Component library < Miscellaneous < Miscellaneous < Rectangle
Component library
Miscellaneous
Rectangles are graphic primitives, which can also be used within circuit diagrams.  
Related Topic  Rectangles 77   
Rectangle
Rectangle
Component library
Miscellaneous

p2_6_1_16.ct
Component library < Miscellaneous < Miscellaneous < Ellipse
Component library
Miscellaneous
Ellipses are graphic primitives, which can also be used within circuit diagrams.  
Related Topic  Ellipses 78   
Ellipse
Ellipse
Component library
Miscellaneous

p2_6_1_17.ct
Component library < Miscellaneous < Miscellaneous < Bitmap
Component library
Miscellaneous
In FluidSIM images, as with all other components and objects, can be inserted, positioned, moved, rotated and mirrored. In addition, images such as rectangles 77 and ellipses 78 are freely scalable.  
Related Topic  Embedding Pictures 815   
Bitmap
Bitmap
Component library
Miscellaneous

p2_6_1_2.ct
Component library < Miscellaneous < Miscellaneous < Valve solenoid
Component library
Miscellaneous
The valve solenoid switches the valve.   By means of a label the valve solenoid can be linked to a valve that is solenoid operated.  
Related Topics  4/2-way solenoid valve (i) p2_1_4_1   4/2-way solenoid valve (ii) p2_1_4_2   4/3-way solenoid valve with shutoff position (i) p2_1_4_3   4/3-way solenoid valve with shutoff position (ii) p2_1_4_4   4/3-way solenoid valve with floating position (i) p2_1_4_5   4/3-way solenoid valve with floating position (ii) p2_1_4_6   4/3-way solenoid valve with bypass position (i) p2_1_4_7   4/3-way solenoid valve with bypass position (ii) p2_1_4_8   Coupling Hydraulics, Electrics and Mechanics 49   
Valve solenoid
Valve solenoid
Component library
Miscellaneous

p2_6_1_3.ct
Component library < Miscellaneous < Miscellaneous < Proportional valve solenoid, position controlled
Component library
Miscellaneous
In FluidSIM the proportional valve solenoid is coupled to the respective continuous directional valve with the help of a label. The required slide position is predetermined via a voltage signal. The valve slide distance is position controlled. The control and amplifier component is integrated in the valve.  
Related Topics  4/3-way regulating valve p2_1_9_1   Coupling Hydraulics, Electrics and Mechanics 49   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional valve solenoid, position controlled
Proportional valve solenoid, position controlled
Component library
Miscellaneous

p2_6_1_4.ct
Component library < Miscellaneous < Miscellaneous < Proportional amplifier, 1-channel
Component library
Miscellaneous
The amplifier is used to control proportional valves. For this purpose, nominal values (voltage signals) from 0 V to +10 V are transformed into the necessary magnetic current for the proportional valves. In FluidSIM the amplifier is coupled to the respective valve with the help of a label. The maximum current at the amplifier output is hereby automatically adjusted in relation to the coupled valve. A step current relative to the maximum current can be specified, in order to compensate the positive overlap of proportional valves. The amplifier requires a power supply of 24 V.  
Related Topics  Proportional pump p2_1_1_5   Proportional throttle valve p2_1_9_3   Proportional pressure relief valve p2_1_9_4   Proportional pressure relief valve, piloted p2_1_9_5   Proportional pressure reducing valve, piloted p2_1_9_6   Coupling Hydraulics, Electrics and Mechanics 49   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional amplifier, 1-channel
Proportional amplifier, 1-channel
Component library
Miscellaneous

p2_6_1_5.ct
Component library < Miscellaneous < Miscellaneous < Proportional amplifier, 2-channel
Component library
Miscellaneous
The amplifier is used to control proportional valves with two magnets. For this purpose, nominal values (voltage signals) from -10 V to +10 V are transformed into the necessary magnetic current for the proportional valves. Output A is gated at a nominal value between 0 V and -10 V, output B between 0 V and -10 V. In FluidSIM the amplifier is coupled to the respective valve with the help of two labels. The maximum currents at the amplifier outputs are hereby automatically adjusted in relation to the coupled valves. A step current relative to the maximum current can be specified, in order to compensate the positive overlap of proportional valves. The amplifier requires a power supply of 24 V.  
Related Topics  4/3-way proportional valve p2_1_9_2   Coupling Hydraulics, Electrics and Mechanics 49   Open-loop and Closed-loop Control by using Continuous Valves 814   
Proportional amplifier, 2-channel
Proportional amplifier, 2-channel
Component library
Miscellaneous

p2_6_1_6.ct
Component library < Miscellaneous < Miscellaneous < Valve solenoid (ladder)
Component library
Miscellaneous
The valve solenoid switches the valve.   By means of a label the valve solenoid can be linked to a valve that is solenoid operated.  
Related Topics  4/2-way solenoid valve (i) p2_1_4_1   4/2-way solenoid valve (ii) p2_1_4_2   4/3-way solenoid valve with shutoff position (i) p2_1_4_3   4/3-way solenoid valve with shutoff position (ii) p2_1_4_4   4/3-way solenoid valve with floating position (i) p2_1_4_5   4/3-way solenoid valve with floating position (ii) p2_1_4_6   4/3-way solenoid valve with bypass position (i) p2_1_4_7   4/3-way solenoid valve with bypass position (ii) p2_1_4_8   Coupling Hydraulics, Electrics and Mechanics 49   
Valve solenoid (ladder)
Valve solenoid (ladder)
Component library
Miscellaneous

p2_6_1_7.ct
Component library < Miscellaneous < Miscellaneous < Distance rule
Component library
Miscellaneous
The distance rule is a device for attaching switches at the cylinder. The labels at the distance rule define links to the actual proximity switches or limit switches in the electrical circuit.  
Related Topics  Switches at Cylinders 52   Double acting cylinder p2_1_10_2   
Distance rule
Distance rule
Component library
Miscellaneous

p2_6_1_8.ct
Component library < Miscellaneous < Miscellaneous < Status indicator
Component library
Miscellaneous
In Edit Mode, the status indicator is automatically displayed at those components that are actuated in the circuit's initial position.  
Related Topics  Break switch p2_2_4_1   Magnetic proximity switch p2_2_9_1   
Status indicator
Status indicator
Component library
Miscellaneous

p2_6_1_9.ct
Component library < Miscellaneous < Miscellaneous < Cam switch
Component library
Miscellaneous
In Edit Mode, the cam switch is automatically displayed at those mechanically operated way valves that are actuated in the circuit's initial position.  
Related Topics  2/2-way stem-Actuated valve (i) p2_1_3_1   2/2-way stem-Actuated valve (ii) p2_1_3_2   
Cam switch
Cam switch
Component library
Miscellaneous

p3.ct
Didactics Material
Didactics Material
Didactics Material
Educational films
Basics and working principles
Didactics Material

p3_1.ct
Didactics material < Basics and working principles
Didactics material
Basics and working principles
Didactics material
Basics and working principles
Applications
Components of a Hydraulic Plant
Symbols
Some Physical Fundamentals
Components of a Power Unit
Fundamentals of Valves
Pressure Valves
Way Valves
Shutoff Valves
Flow Valves
Hydraulic Cylinders and Motors
Gauges
Exercises

p3_1_1.ct
Didactics material < Basics and working principles < Applications
Didactics material
Basics and working principles
Didactics material
Applications
Applications
Lathe
Press with elevated reservoir
Mobile hydraulics: Excavator

p3_1_10.ct
Didactics material < Basics and working principles < Flow Valves
Didactics material
Basics and working principles
Didactics material
Flow Valves
Flow Valves
Needle restrictor
Gap restrictor with helix
Circuit diagram: Flow division using restrictor
Flow control valve
One-way flow control valve (1)
One-way flow control valve (2)
2-way flow control valve (1)
2-way flow control valve (2)
2-way flow control valve (3)
Circuit diagram: 2-way flow control valve
2-way flow control valve 

p3_1_10_1.ct
Didactics material < Basics and working principles < Flow Valves < Needle restrictor
Didactics material
Basics and working principles
Didactics material
Throttle and orifice valves are used to achieve a certain pressure drop. This is done by creating a specific flow resistance. The needle flow control valve shown generates considerable friction due to its long narrowing. This means that the action of the flow control valve is difficult to adjust due to the fact that a small adjustment produces a large change in cross-section.      One advantage is the simple and inexpensive design. Needle flow control valves can be used if the above- mentioned negative properties can be ignored for the purposes of a given control task.  
[140]  Needle restrictor
Needle restrictor
Flow Valves

p3_1_10_10.ct
Didactics material < Basics and working principles < Flow Valves < Circuit diagram: 2-way flow control valve
Didactics material
Basics and working principles
Didactics material
The model circuit diagram shows the arrangement of a 2-way flow control valve in the piston-side supply line in order to achieve a constant feed speed even under varying load. A non-return valve is fitted in the by-pass to allow the flow control valve to be by-passed on the return stroke.      
[149]  Circuit diagram: 2-way flow control valve
Circuit diagram: 2-way flow control valve
Flow Valves

p3_1_10_11.ct
Didactics material < Basics and working principles < Flow Valves < 2-way flow control valve 
Didactics material
Basics and working principles
Didactics material
The advancing piston rod encounters a load half-way through its stroke. The flow control valve nonetheless ensures that the advance speed remains constant. From 0 to 2 seconds (shown at bottom right) the piston rod is unloaded and the pressure conditions remain constant. When the piston rod encounters the load, the pressure p3 rises at the outlet of the flow control valve. (In order to allow the rapid control operations to be shown more clearly, the time scale now changes to 1/100ths of a second.) The flow control valve briefly raises the pressure p2 downstream of the adjustable restrictor. Following this, the regulating restrictor moves to the left, and p2 falls back to its original value, i.e. the pressure difference between p1 and p2 remains constant. The regulating operation shown is repeated a number of times, as the result of which p3 increases to 2.5 MPa (25 bar) in several steps and the regulating restrictor opens more and more. (At the point at which 2.5 MPa (25 bar) is reached, the time scale changes back to 0.1 seconds.) The piston rod now travels under load just as fast as previously without load.      
[150]  2-way flow control valve
2-way flow control valve 
Flow Valves

p3_1_10_2.ct
Didactics material < Basics and working principles < Flow Valves < Gap restrictor with helix
Didactics material
Basics and working principles
Didactics material
Its short narrowing means that the action of this gap flow control valve is virtually independent of viscosity. The helix provides precise adjustability, since adjustment from fully open to fully closed requires a 360º turn. The helix is, however, very costly to produce.      
[141]  Gap restrictor with helix
Gap restrictor with helix
Flow Valves

p3_1_10_3.ct
Didactics material < Basics and working principles < Flow Valves < Circuit diagram: Flow division using restrictor
Didactics material
Basics and working principles
Didactics material
Throttle and orifice valves control the volumetric flow rate in conjunction with a pressure relief valve. The PRV opens when the resistance of the flow control valve becomes greater than that of the opening pressure set on the PRV. This produces a division of flow.      The volumetric flow to the load device varies, i.e. the action of flow control valves is load-dependent.  
[142]  Circuit diagram: Flow division using restrictor
Circuit diagram: Flow division using restrictor
Flow Valves

p3_1_10_4.ct
Didactics material < Basics and working principles < Flow Valves < Flow control valve
Didactics material
Basics and working principles
Didactics material
Actual photograph of a flow control valve.      
[143]  Flow control valve
Flow control valve
Flow Valves

p3_1_10_5.ct
Didactics material < Basics and working principles < Flow Valves < One-way flow control valve (1)
Didactics material
Basics and working principles
Didactics material
The one-way flow control valve is a combination of an orifice or throttle valve and a non-return valve. In the closed direction shown of the non-return valve, the volumetric flow passes via the variable throttle gap, which creates a considerable resistance.      Speed reduction can be achieved by using a one-way flow control valve in conjunction with a pressure relief valve or a variable-delivery pump. The pressure rises upstream of the flow control valve until the PRV opens and routes part of the flow to the tank.  
[144]  One-way flow control valve (1)
One-way flow control valve (1)
Flow Valves

p3_1_10_6.ct
Didactics material < Basics and working principles < Flow Valves < One-way flow control valve (2)
Didactics material
Basics and working principles
Didactics material
In the reverse direction, from B to A, flow is unrestricted, since the ball in the one-way flow control valve allows free flow (non-return function).      One-way flow control valves are available with a fixed restrictor and with variable flow control.  
[145]  One-way flow control valve (2)
One-way flow control valve (2)
Flow Valves

p3_1_10_7.ct
Didactics material < Basics and working principles < Flow Valves < 2-way flow control valve (1)
Didactics material
Basics and working principles
Didactics material
Flow control valves have the task of providing constant volumetric flow independently of pressure changes at the inlet or outlet of the valve. This is achieved firstly by means of an adjustable restrictor which is set to the desired volumetric flow. In order to keep the pressure drop across the throttle point constant, a second regulating restrictor (pressure compensator) is also required. The illustration shows the valve in its normal position.      2-way flow control valves always operate in conjunction with a pressure relief valve. The part of the flow which is not required is discharged via the PRV.  
[146]  2-way flow control valve (1)
2-way flow control valve (1)
Flow Valves

p3_1_10_8.ct
Didactics material < Basics and working principles < Flow Valves < 2-way flow control valve (2)
Didactics material
Basics and working principles
Didactics material
When fluid flows through the valve, the pressure drop across the adjustable restrictor is kept constant by the pressure compensator, which varies the resistance at the upper throttle point in accordance with the load at the inlet or outlet.      See also the animation 150 p3_1_10_11 for this topic.  
[147]  2-way flow control valve (2)
2-way flow control valve (2)
Flow Valves

p3_1_10_9.ct
Didactics material < Basics and working principles < Flow Valves < 2-way flow control valve (3)
Didactics material
Basics and working principles
Didactics material
In the case of this flow control valve, the pressure difference is kept constant by a adjustable restrictor, i.e. between p1 and p2. If the pressure p3 rises as the result of an external load, the overall resistance of the valve is reduced by opening the regulating restrictor.      
[148]  2-way flow control valve (3)
2-way flow control valve (3)
Flow Valves

p3_1_11.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors
Didactics material
Basics and working principles
Didactics material
Hydraulic Cylinders and Motors
Hydraulic Cylinders and Motors
Single acting cylinder
Plunger cylinder
Double acting cylinder
Double acting cylinder with end position cushioning
End position cushioning (1)
End position cushioning (2)
End position cushioning 
Double acting cylinder
Automatic bleed valve 

p3_1_11_1.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < Single acting cylinder
Didactics material
Basics and working principles
Didactics material
In the case of a single acting cylinder, only the piston side is pressurized with hydraulic fluid. The cylinder can thus carry out work only in one direction. The fluid which flows into the piston chamber causes a pressure to build up the surface of the piston. The piston travels into its forward end position. The return stroke is effected by a spring, the dead weight of the piston rod or an external load.      
[151]  Single acting cylinder
Single acting cylinder
Hydraulic Cylinders and Motors

p3_1_11_2.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < Plunger cylinder
Didactics material
Basics and working principles
Didactics material
In the case of plunger cylinders, the piston and rod form a single component. Due to the design of the cylinder, the return stroke can only be effected by external forces. The cylinders can therefore generally be installed only vertically.      
[152]  Plunger cylinder
Plunger cylinder
Hydraulic Cylinders and Motors

p3_1_11_3.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < Double acting cylinder
Didactics material
Basics and working principles
Didactics material
In the case of double acting cylinders, both piston surfaces can be pressurized. A working movement can thus be performed in both directions.      With double acting cylinders with a single-sided piston rod, different forces and speeds are obtained on the advance and return strokes due to the difference in area between the piston surface and annular piston surface.  
[153]  Double acting cylinder
Double acting cylinder
Hydraulic Cylinders and Motors

p3_1_11_4.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < Double acting cylinder with end position cushioning
Didactics material
Basics and working principles
Didactics material
Cylinder with end position cushioning are used to brake high stroke speeds smoothly and prevent hard impacts at the end of the stroke. Shortly before the end position is reached, the cross- section for the outflow of fluid is reduced by the built-in cushioning pistons and then finally closed. The hydraulic fluid is then forced to escape through a flow control valve.      
[154]  Double acting cylinder with end position cushioning
Double acting cylinder with end position cushioning
Hydraulic Cylinders and Motors

p3_1_11_5.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < End position cushioning (1)
Didactics material
Basics and working principles
Didactics material
The piston is a short distance before its end position; the hydraulic fluid on the piston-rod side must escape via the adjustable flow control valve above the piston rod      This type of end position cushioning is used for stroke speed between 6 m/min and 20 m/min. At higher speed, additional cushioning or braking devices must be used.  
[155]  End position cushioning (1)
End position cushioning (1)
Hydraulic Cylinders and Motors

p3_1_11_6.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < End position cushioning (2)
Didactics material
Basics and working principles
Didactics material
The piston rod is on its return stroke; in this flow direction, the non-return valve below the piston rod is opened, thus by-passing the flow control valve. The piston rod retracts at maximum speed.      
[156]  End position cushioning (2)
End position cushioning (2)
Hydraulic Cylinders and Motors

p3_1_11_7.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < End position cushioning 
Didactics material
Basics and working principles
Didactics material
The illustration shows first the advance of the piston rod from a mid-position to the forward end position, with cushioning at the end of the advance movement. The non-return valve is open during the return stroke.      In addition the animation shows the opening of the pressure limiter after a certain pressure has been built up on the outlet side by the cushioning piston.  
[157]  End position cushioning
End position cushioning 
Hydraulic Cylinders and Motors

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Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < Double acting cylinder
Didactics material
Basics and working principles
Didactics material
Actual photograph of a double acting cylinder.      
[158]  Double acting cylinder
Double acting cylinder
Hydraulic Cylinders and Motors

p3_1_11_9.ct
Didactics material < Basics and working principles < Hydraulic Cylinders and Motors < Automatic bleed valve 
Didactics material
Basics and working principles
Didactics material
When the cylinder is retracted, the piston of the bleed valve is closed. It is lifted as the piston rod advances. Air can then escape via the bleed hole until the hydraulic fluid reaches the piston and pushes it upwards. In the forward end position, the piston is pushed fully upwards by the hydraulic fluid and thus provides an external seal.      Bleed valves should be fitted at the highest point in a piping system, since this is where any trapped air will collect.  
[159]  Automatic bleed valve
Automatic bleed valve 
Hydraulic Cylinders and Motors

p3_1_12.ct
Didactics material < Basics and working principles < Gauges
Didactics material
Basics and working principles
Didactics material
Gauges
Gauges
Piston pressure gauge
Bourdon-tube pressure gauge
Flow meter

p3_1_12_1.ct
Didactics material < Basics and working principles < Gauges < Piston pressure gauge
Didactics material
Basics and working principles
Didactics material
Pressure gauges operate on the principle that pressure acting on a given area will produce a given force. In the case of piston pressure gauges, the pressure acts on a piston against the force of a spring. The pressure value is now shown on a scale either by the piston itself or by a pointer driven magnetically by the piston.      
[160]  Piston pressure gauge
Piston pressure gauge
Gauges

p3_1_12_2.ct
Didactics material < Basics and working principles < Gauges < Bourdon-tube pressure gauge
Didactics material
Basics and working principles
Didactics material
Most pressure gauges operate on the principle of a Bourdon tube. When hydraulic fluid flows into the tube, an identical pressure is produced throughout. Due to the difference in area between the outer and inner curved surfaces, the tube is bent. This movement is transferred to a pointer.      This type of gauge is not protected against overload. A cushioning restrictor must be installed in the inlet connection prevent pressure surges from damaging the tube.  
[161]  Bourdon-tube pressure gauge
Bourdon-tube pressure gauge
Gauges

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Didactics material < Basics and working principles < Gauges < Flow meter
Didactics material
Basics and working principles
Didactics material
The flow of oil to be measured passes through a movable orifice. The orifice consists of a fixed cone and a hollow piston mounted on a spring. The piston is pressed against the spring in proportion to the flow rate concerned. The measuring error of this type of flow meter is approx. 4%. Measuring turbines, oval disk meters or toothed-wheel gauges are used when higher accuracy is required.      
[162]  Flow meter
Flow meter
Gauges

p3_1_13.ct
Didactics material < Basics and working principles < Exercises
Didactics material
Basics and working principles
Didactics material
Exercises
Exercises
Exercise: Horizontal grinding machine (pump delivery)
Exercise: Bending machine (directly-controlled pressure relief valve)
Exercise: Roller conveyor (flow resistance)
Exercise: Embossing press (activation of a single acting cylinder)
Exercise: Ladle (activation of a double acting cylinder)
Exercise: Paint drying oven (4/3-way valve)
Exercise: Clamping device (closing speed)
Exercise: Hydraulic crane (speed reduction)
Exercise: Feed control for a lathe (speed control)
Exercise: Planing machine (by-pass circuit)
Exercise: Drilling machine (pressure regulator)

p3_1_13_1.ct
Didactics material < Basics and working principles < Exercises < Exercise: Horizontal grinding machine (pump delivery)
Didactics material
Basics and working principles
Didactics material
The slide on a horizontal grinding machine is hydraulically actuated. A machine operator determines that the reciprocating movement of the machine is no longer reaching the desired speed. A possible cause of this is reduced pump delivery. To investigate this, it is necessary to plot a characteristic curve for the pump and compare this with the values achieved during initial commissioning. As an additional exercise, the circuit diagram and parts list for the necessary test assembly should be prepared.  In order to draw the characteristic curve for the pump, the volumetric flow of hydraulic fluid delivered by the pump (Q) is plotted against the operating pressure achieved (p). The manufacturer's characteristic curve exhibits a slight downward gradient, since the new pump manifests increasing internal leakage losses as necessary to provide internal lubrication. The newly-plotted curve shows a clear deviation; the leakage oil losses have become greater at higher operating pressures, the volumetric efficiency has become worse. The main reason for this is pump wear. Regarding the circuit diagram for the test assembly: The adjustable flow control valve 1V3 is adjusted in such a way that the pressure gauge 1Z1 shows the desired system pressure. The pressure relief valve 1V2 is used to limit the system pressure, while valve 1V1 acts as a safety valve for the pump.  The measured values taken as the basis for this exercise do not allow for the characteristic curve of the electric motor. The motor characteristic thus forms part of the calculated error.    
[163]  Exercise: Horizontal grinding machine (pump delivery)
Exercise: Horizontal grinding machine (pump delivery)
Exercises

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Didactics material < Basics and working principles < Exercises < Exercise: Planing machine (by-pass circuit)
Didactics material
Basics and working principles
Didactics material
The sliding bed of a parallel planing machine is actuated with the aid of a hydraulic control system. The power section of this hydraulic control system consists of a double acting differential cylinder. The area ratio of the full piston surface of this cylinder to the annular piston surface is 2:1. Since the piston-rod chamber is only half the volume of the piston chamber, the return stroke is twice as fast as the advance stroke. Machining has previously been carried out only during the advance stroke. In future, working movements are to be carried out in both directions. To make this possible, the hydraulic control system must be modified so that forward and return strokes are at the same speed. The speed should now also be adjustable. The connecting lines should be added to the given circuit diagram. The mode of operation of the circuit in the three switching positions should be described and the various piston speeds and forces compared.  In order to achieve the same speed on the advance and return strokes, a differential circuit (by-pass circuit) can be used with differential cylinders with an area ratio of 2:1. Picture 116.2 The second picture shows the principle of a by-pass circuit with a 3/2-way valve. In the case of the parallel planing machine, the necessary differential circuit can be achieved by using the mid-position of a 4/3-way valve (A, B and P connected, T closed). In this switching position (advance stroke), the piston speed and force are twice as high as in the right-hand switching position (return stroke). In the left-hand switching position, on the other hand, the advance stroke is half as fast and the force twice as great as in the other two switching positions. The speed for the advance and return strokes can be adjusted by means of a flow control valve fitted upstream.  It should also be noted that only half the force is available on the advance stroke at the mid-position. In the case of a tractive load, the by-pass position has the advantage that the piston is hydraulically clamped. Differential circuits are used not only as synchronization circuits but also as rapid-traverse circuits when, for example, different speeds are required in the same direction with constant pump delivery. If it is desired to calculate forces and piston speeds using concrete values, the model values given in the TP 501 textbook can be used for this purpose.    
[172]  Exercise: Planing machine (by-pass circuit)
Exercise: Planing machine (by-pass circuit)
Exercises

p3_1_13_11.ct
Didactics material < Basics and working principles < Exercises < Exercise: Drilling machine (pressure regulator)
Didactics material
Basics and working principles
Didactics material
The drill feed and clamping device of a drilling machine are hydraulically actuated. The hydraulic control system contains two cylinders, a clamping cylinder 1A and a feed cylinder 2A. The clamping pressure at cylinder 1A must be adjustable, since different workpiece clamping forces are required. A pressure regulator is used for this. The return stroke of the clamping cylinder must be at maximum speed. The drilling feed must be adjustable for various feed speeds, which must however remain constant under varying load. It should also be noted that the drive spindle fitted to the piston rod of the drilling cylinder acts as a tractive load. The return stroke of the drilling cylinder should also be at maximum speed. A circuit should be drafted with the above-mentioned characteristics.  Pressure regulators can as general principle be used to reduce the general system pressure in a part of a hydraulic installation. If we consider the two control chains for the drilling machine without pressure regulation, we can observe the following undesirable effects: When 1V1 is actuated, the workpiece is first clamped at full system pressure. If 2V1 is now actuated, the system pressure will drop to the operating pressure of the drilling cylinder. The same applies to the pressure at the clamping cylinder. If the circuit is expanded to include the pressure regulator 1V3, this enables the clamping pressure to be adjusted. The system pressure upstream of the PRV will, however, continue to fall during the advance stroke of 2A. In order to maintain the preset clamping pressure at outlet A of the PRV reliably, the pressure at inlet P must be higher than this. This can be achieved by fitting the additional flow control valve 0V2 upstream of the final control element 2V1. Maximum return-stroke speed is achieved for the clamping cylinder by means of 1V2, which is used to by-pass 1V3. The flow control valve 2V3 means that the advance-stroke speed of the drilling cylinder is independent of load and adjustable. Due to the tractive load of the attached spindle, however, an additional PRV must be fitted as a back-pressure valve. The non-return valves 2V2 and 2V5 provide a by-pass during the return stroke and allow maximum speed to be achieved during this.  A parts list can be specified to help in the drafting of this circuit.    
[173]  Exercise: Drilling machine (pressure regulator)
Exercise: Drilling machine (pressure regulator)
Exercises

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Didactics material < Basics and working principles < Exercises < Exercise: Bending machine (directly-controlled pressure relief valve)
Didactics material
Basics and working principles
Didactics material
A bending machine is used to bend steel plates. The bending tools are driven by hydraulic cylinders. It is now desired to use the bending machine for considerably thicker steel plates than before. This requires a hydraulic system pressure of 45 bar against the previous 30 bar. According to the manufacturer's data, the pump used is suitable for the higher operating pressure. Testing reveals, however, that the bending process is now much too slow. In this case, leakage losses in the piping or directional control valve are ruled out as the cause of the problem. A directly-controlled pressure relief valve (PRV) is installed as a safety valve. Measurements of the volumetric flow (Q) as a function of pressure (p) are available for this valve. A characteristic curve can than be used to determine whether the loss of speed in the bending process is due to the PRV.  The volumetric flow which is discharged to the tank when the PRV opens is entered on the horizontal axis. The characteristic curve shows that the opening point of the PRV is 44 bar, although it is set to 50 bar. This means that part of the pump delivery is diverted at pressures greater than 44 bar. Pressures of more than 44 bar are achieved during the bending process. Since, however, the flow is divided from 44 bar onwards, the volumetric flow to the cylinder is reduced from this point and the bending process slows down. Measure to be taken: The PRTV can be set to 60 bar if the overall installation has been designed for this higher pressure. Flow diversion will then take place from a pressure of 54 bar onwards.  An alternative solution would be to use a valve with a different response pressure.    
[164]  Exercise: Bending machine (directly-controlled pressure relief valve)
Exercise: Bending machine (directly-controlled pressure relief valve)
Exercises

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Didactics material < Basics and working principles < Exercises < Exercise: Roller conveyor (flow resistance)
Didactics material
Basics and working principles
Didactics material
Steel blocks are transported on a roller conveyor. A hydraulic transfer station makes it possible to transfer blocks from one track to another. A pressure of at least 30 bar is required for the transfer of blocks by means of hydraulic cylinders. Every component through which the hydraulic fluid flows represents a resistance and causes a constant pressure loss. The question is, what pressure is to be set at the pressure relief valve.  The total resistance is the sum of all the individual resistances. The resistance must be determined separately for the advance and return strokes. The overall balances do not include data for the pressure losses at the 4/2-way valve. These can be determined from the flow characteristic for the 4/2-way valve, based on a volumetric flow of 8 l/min. In the calculation, allowance must be made for the resistance of the directional control valve on the inlet and outlet sides respectively. Allowance must also be made for the pressure intensification factor of 2:1 in the case of the differential cylinder. This enables values to be calculated as shown in the solution figure. In the case of the advance stroke, 6 bar hysteresis for the PRV (see exercise 164 p3_1_13_2) must be added to the calculated 42.5 bar in order to ensure that the opening pressure is higher than the required operating pressure. The value finally chosen is 50 bar in order to make allowance for unknown variables such as pipe elbows and the static friction in the cylinder.  In order to keep pressure losses in large installations to a minimum, it is advisable to select valves on the basis of their flow characteristics. It is better to select a valve which is one size too large than to accept large pressure losses. This furthermore reduces wear resulting from cavitation in the valves.    
[165]  Exercise: Roller conveyor (flow resistance)
Exercise: Roller conveyor (flow resistance)
Exercises

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Didactics material < Basics and working principles < Exercises < Exercise: Embossing press (activation of a single acting cylinder)
Didactics material
Basics and working principles
Didactics material
Additional hydraulic components are to be added to an embossing press to eject the finished workpieces. A single acting cylinder (1A) is to be fitted for this purpose. A proposed solution in the form of a circuit diagram with a 2/2-way valve is to be examined to see if it is suitable for this control problem. Following this, a circuit diagram with a 3/2-way valve as final control element is to be developed and a parts list prepared. A comparison is to be made of the behavior of these two circuits during the advance and return strokes.  When a 2/2-way valve is used to activate a single acting cylinder, the final control element must be reversed and the hydraulic power unit switched off in order to retract the piston rod. The load acting on the piston rod must be larger than the resistance of the directional control valve. This solution cannot be used due to the presence of the second control chain (embossing cylinder). If a 3/2-way valve is used, a direct switch-over can be made from the advance stroke to the return stroke without switching off the hydraulic power unit. Halting at overlap positions, on the other hand (which are not required here), would be possible only by switching off the hydraulic power unit.  The non-return valve fitted in each case protects the pump against oil back-pressure. This is necessary in case the hydraulic power unit is switched off with the cylinder advanced and under load.    
[166]  Exercise: Embossing press (activation of a single acting cylinder)
Exercise: Embossing press (activation of a single acting cylinder)
Exercises

p3_1_13_5.ct
Didactics material < Basics and working principles < Exercises < Exercise: Ladle (activation of a double acting cylinder)
Didactics material
Basics and working principles
Didactics material
Liquid aluminum is transferred from a holding furnace into a channel leading to a die-casting machine. A ladle is required for this. A double acting cylinder is used to enable the ladle to carry out the appropriate movements. A circuit diagram is provided for the activation of the cylinder with a 4/2-way valve as final control element. This must be examined to see if it is suitable for the control task concerned. The ladle must not be allowed to dip into the furnace when the valve is not actuated. A circuit diagram with a back-pressure valve must be developed to cater for the case in which the ladle is very heavy.  The requirements of the exercise are met by the first circuit diagram only if the ladle represents a light load. If the ladle is very heavy, the advance speed could rise to an unacceptably high level during the advance stroke of the piston rod (ladle moving towards furnace), and the ladle could as a result plunge too quickly into the molten metal. This can be prevented by installing a back- pressure valve in the B line between the valve and cylinder (tractive load).  If, as is required in this exercise, the power component must positively assume a defined end position when the installation is at rest, valves with spring return must be used, as in this case. Here, a 4/2-way valve with spring return has been used, since this ensures that the cylinder remains in the desired position if the hydraulic power unit is switched on unexpectedly. The required cylinder diameter and the return speed of the piston rod can also be calculated as additional optional tasks in the exercise: see the model calculations in the textbook.    
[167]  Exercise: Ladle (activation of a double acting cylinder)
Exercise: Ladle (activation of a double acting cylinder)
Exercises

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Didactics material < Basics and working principles < Exercises < Exercise: Paint drying oven (4/3-way valve)
Didactics material
Basics and working principles
Didactics material
Workpieces are fed continuously through a paint drying oven on a conveyor belt. In order to minimize the heat loss through the door, this should be opened only as much as required by the height of the workpieces. The hydraulic control system should be designed so that the door can be held reliably in position for a long period of time without slipping down. Firstly, a 4/3-way valve with suitable mid-position functions should be selected as a final control element. Secondly, a delockable non-return valve should be provided in the circuit diagram to act as a hydraulic safety device to prevent slippage of the door under load (i.e. its own weight) over a long period of time as the result of leakage losses in the directional control valve. The question is, which type of 4/3-way valve has a suitable mid-position function?  A 4/3-way valve with an “all ports closed” mid-position will solve the problem only if a poppet valve is used. If a slide valve would be used, the oven door would slip down slowly as the result of internal leakage losses.  The second solution would be to fit a delockable non- return valve in the supply line to the piston rod side of the cylinder downstream of the directional control valve. In order to ensure that the non-return valve closes immediately when the door stops, both the outlets A and B of the directional control valve to the tank must be de-pressurized (A, B and T connected, P closed).    
[168]  Exercise: Paint drying oven (4/3-way valve)
Exercise: Paint drying oven (4/3-way valve)
Exercises

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Didactics material < Basics and working principles < Exercises < Exercise: Clamping device (closing speed)
Didactics material
Basics and working principles
Didactics material
Workpieces are clamped by a hydraulic cylinder. The closing speed must be reduced in order to prevent damage to the workpieces. The opening speed must, however, be maintained. The question here is how to incorporate the necessary one-way flow control valve in the circuit. Possible solutions must be examined to see what thermal side- effects occur and to determine the pressure load placed on the components concerned.  The advance stroke can as a general principle be made slower by using either inlet or outlet flow control. Either solution can be used in this control; in comparison with outlet flow control, inlet flow control has the advantage that no pressure intensification will take place. The oil heated at the throttle point will, however, then pass through the power component. The resulting expansion of material is not, however, of significance for this simple vice. If the solution with outlet flow control is selected, it should be borne in mind that pressure intensification will take place in accordance with the area ratio of the differential cylinder of 2:1. The pressure relief valve will respond, i.e. flow division will occur, only when a pressure has built up on the piston-rod side which is approximately twice as high as the system pressure set on the PRV. The cylinder, flow control valve and connectors used must therefore be suitable for this intensified pressure.  Precision drives for machine tools are a good example of cases in which it is essential to make allowance for expansion of the material of power components due to the passage through these of heated oil.    
[169]  Exercise: Clamping device (closing speed)
Exercise: Clamping device (closing speed)
Exercises

p3_1_13_8.ct
Didactics material < Basics and working principles < Exercises < Exercise: Hydraulic crane (speed reduction)
Didactics material
Basics and working principles
Didactics material
Press tools of varying weights are inserted into a press by means of a hydraulic crane. A double acting cylinder raises and lowers the load. During the commissioning of the hydraulic crane, it has become apparent that the advance speed of the piston rod is too high. The solutions have been proposed to reduce this speed; a circuit with exhaust flow control and a circuit with a back-pressure valve. A suitable solution must be selected and reasons stated for this choice. Since the second solution is not capable of operating in this form, this must be rectified by correcting the circuit diagram.  If the solution with exhaust flow control is selected, it must be borne in mind that the cylinder, flow control valve and connectors must be suitable for this intensified pressure. The solution chosen is the circuit with the back-pressure valve; in this case, the load is clamped hydraulically and a pressure-intensification effect does not occur, since the pressure can be adjustable by means of the pressure relief valve as appropriate to the load. A non-return valve must be installed to provide a by-pass on the return stroke.  Inlet flow control cannot be used to control a tractive load; the load forces oil out of the piston-rod chamber faster than oil can flow into the piston chamber. Vacuum is created and air will escape.    
[170]  Exercise: Hydraulic crane (speed reduction)
Exercise: Hydraulic crane (speed reduction)
Exercises

p3_1_13_9.ct
Didactics material < Basics and working principles < Exercises < Exercise: Feed control for a lathe (speed control)
Didactics material
Basics and working principles
Didactics material
The feed movement of a lathe has previously been carried out manually. In future, this is to be performed automatically by a hydraulic control system. The feed movement must be adjustable and remain constant even with changing tool loads. Since a simple throttle valve is not able to provide a constant feed speed under changing load, a 2-way flow control valve must be used. On the basis of a circuit diagram with data for the no- load situation, values for pressures, pressure differences and feed speed under load must be added. The circuit diagram must be modified to ensure that the flow control valve is not operative on the return stroke. Finally, the relationship must be investigated between Q of the PRV and the feed speed and between D p2 and the volumetric flow to the load device.  In order to prevent the flow control valve from acting as a resistance on the return stroke, a non-return valve is installed parallel to this as a by-pass. The pressure at the PRV remains constant despite the effect of the load. The outlet flow from this is therefore a constant 7 l/min. A constant volumetric flow Q at the PRV in turn means a constant volumetric flow to the load device and thus constant feed speed. Regarding the last question: No matter whether operation is with or without a load, the pressure drop D p2 at the adjustable throttle remains constant. A constant pressure drop means a constant volumetric flow.  Regarding the necessity for the non-return valve in the by-pass: When flow passes through 2-way flow control valves in the reverse direction, they act either as flow control valves if the regulating restrictor is fully open or non-return valves if the regulating restrictor is closed.    
[171]  Exercise: Feed control for a lathe (speed control)
Exercise: Feed control for a lathe (speed control)
Exercises

p3_1_1_1.ct
Didactics material < Basics and working principles < Applications < Lathe
Didactics material
Basics and working principles
Didactics material
Machine-tool construction is a typical area of application of hydraulics. With modern CNC machine tools, the tools and workpieces are clamped by hydraulic means. Feed motions and the spindle drive can also be hydraulically powered.      This can also serve as an example of hydraulic circuit with two pressure ranges, for example, 3 MPa (30 bar) for machining and 9 MPa (90 bar) for clamping.  
[1]  Lathe
Lathe
Applications

p3_1_1_2.ct
Didactics material < Basics and working principles < Applications < Press with elevated reservoir
Didactics material
Basics and working principles
Didactics material
This is an application in which extremely high forces are required. Due to the suspended cylinder and the tractive load, special measures are required for the activation of the advance stroke. This in turn requires specially-designed press drives.      A special feature is the elevated reservoir, which utilizes the static pressure in the pressure medium.  
[2]  Press with elevated reservoir
Press with elevated reservoir
Applications

p3_1_1_3.ct
Didactics material < Basics and working principles < Applications < Mobile hydraulics: Excavator
Didactics material
Basics and working principles
Didactics material
On this hydraulic excavator, not only all working movements (linear drives) but also the propulsion of the vehicle (rotary drive) are hydraulically powered. The primary drive of the excavator is an internal-combustion engine.      A model calculation can be used here to demonstrate an advantage of hydraulics - large forces with relatively small components.  
[3]  Mobile hydraulics: Excavator
Mobile hydraulics: Excavator
Applications

p3_1_2.ct
Didactics material < Basics and working principles < Components of a Hydraulic Plant
Didactics material
Basics and working principles
Didactics material
Components of a Hydraulic Plant
Components of a Hydraulic Plant
Structure of a hydraulic system
Hydraulic power section
Block diagram of a control system
Interaction of components 
Action related numbering
Numbering in accordance with DIN ISO 1219-2
Numbering in accordance with parts list

p3_1_2_1.ct
Didactics material < Basics and working principles < Components of a Hydraulic Plant < Structure of a hydraulic system
Didactics material
Basics and working principles
Didactics material
This simplified block diagram shows the division of hydraulic systems into a signal control section and a hydraulic power section. This signal control section is used to activate the valves in the power control section.      The material depicted in these electronic slides is concerned in the main with the hydraulic power section and the three “levels” of this which are shown.  
[4]  Structure of a hydraulic system
Structure of a hydraulic system
Components of a Hydraulic Plant

p3_1_2_2.ct
Didactics material < Basics and working principles < Components of a Hydraulic Plant < Hydraulic power section
Didactics material
Basics and working principles
Didactics material
The diagram of the hydraulic power section is complemented in this case by a circuit diagram to allow correlation of the various function groups; the power supply section contains the hydraulic pump and drive motor and the components for the preparation of the hydraulic fluid. The energy control section consists of the various valves used to provide control and regulate the flow rate, pressure and direction of the hydraulic fluid. This drive section consists of cylinders or hydraulic motors, depending on the application in question.      
[5]  Hydraulic power section
Hydraulic power section
Components of a Hydraulic Plant

p3_1_2_3.ct
Didactics material < Basics and working principles < Components of a Hydraulic Plant < Block diagram of a control system
Didactics material
Basics and working principles
Didactics material
In analyzing and planning an actual control task, it can be helpful to use a differentiated block diagram showing the actual levels to be found on the machine.      The light arrows show the signal flow, while the solid dark arrows show the energy flow.  
[6]  Block diagram of a control system
Block diagram of a control system
Components of a Hydraulic Plant

p3_1_2_4.ct
Didactics material < Basics and working principles < Components of a Hydraulic Plant < Interaction of components 
Didactics material
Basics and working principles
Didactics material
The animations show the sequences in a basic hydraulic circuit in simplified form - the actuation and spring return of the final control element (4/2-way valve), the advance and return of the drive component (double acting cylinder) and the opening and closing of the pressure relief valve.      The representations of the actuator and final control element are based on the relevant circuit symbols. This can be used as a preparation for the introduction of circuit symbols.  
[7]  Interaction of components
Interaction of components 
Components of a Hydraulic Plant

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Didactics material < Basics and working principles < Components of a Hydraulic Plant < Action related numbering
Didactics material
Basics and working principles
Didactics material
First of all the control chain is numbered sequentially according to the principle. The first actuator is given the supplementary number .0 and the associated final control element the supplementary number .1. The remaining elements get even numbers if they influence the advance stroke and uneven numbers if they influence the return stroke.      The numbering should always be entered in the circuit diagram and also on the machine to enable systematic fault-finding.  
[8]  Action related numbering
Action related numbering
Components of a Hydraulic Plant

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Didactics material < Basics and working principles < Components of a Hydraulic Plant < Numbering in accordance with DIN ISO 1219-2
Didactics material
Basics and working principles
Didactics material
The DIN ISO Standard 1219-2 defines the code structure of the components as a string consisting of the following four parts: number of the plant, number of the circuit, component designation, and component number. If the entire system consists of a single plant only, the plant number may be dropped.      
[9]  Numbering in accordance with DIN ISO 1219-2
Numbering in accordance with DIN ISO 1219-2
Components of a Hydraulic Plant

p3_1_2_7.ct
Didactics material < Basics and working principles < Components of a Hydraulic Plant < Numbering in accordance with parts list
Didactics material
Basics and working principles
Didactics material
Another method used in practice is to number all the components in a hydraulic system consecutively. The numbers then correspond to the numbers in the parts list.      This method is used particularly with complex controls systems, for which a control-chain-related numbering system can not be used due the overlaps involved.  
[10]  Numbering in accordance with parts list
Numbering in accordance with parts list
Components of a Hydraulic Plant

p3_1_3.ct
Didactics material < Basics and working principles < Symbols
Didactics material
Basics and working principles
Didactics material
Symbols
Symbols
Circuit symbols for energy transfer (1)
Circuit symbols for energy transfer (2)
Circuit symbols for energy conversion
Circuit symbols for hydraulic motors
Circuit symbols for single acting cylinders
Circuit symbols for double acting cylinders
Circuit symbols for directional control valves (1)
Circuit symbols for directional control valves (2)
Circuit symbols for directional control valves (3)
Circuit symbols for manual operation
Circuit symbols for mechanical actuation
Circuit symbol for pressure valves
Circuit symbols for flow control valves
Circuit symbols for non-return valves
Circuit symbols for measuring devices

p3_1_3_1.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for energy transfer (1)
Didactics material
Basics and working principles
Didactics material
The symbols shown are used in circuit diagrams for energy transfer and hydraulic-fluid preparation.      In the interests of clarity, the lines in the circuit diagram should be drawn without cross-overs as far as possible.  
[11]  Circuit symbols for energy transfer (1)
Circuit symbols for energy transfer (1)
Symbols

p3_1_3_10.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for manual operation
Didactics material
Basics and working principles
Didactics material
The switching position of a directional control valve can be changed by various actuation methods. The symbol for the valve is accordingly supplemented by a symbol indicating the actuation methods shown, such as pushbuttons and pedals, a spring is always necessary for resetting. Resetting can, however, also be achieved by actuating the valve a second time, for example in the case of valves with hand levers and detents.      The various actuating methods possible are listed in DIN ISO 1219.  
[20]  Circuit symbols for manual operation
Circuit symbols for manual operation
Symbols

p3_1_3_11.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for mechanical actuation
Didactics material
Basics and working principles
Didactics material
This illustration shows the symbols for stem or push button, spring and roller stem.      
[21]  Circuit symbols for mechanical actuation
Circuit symbols for mechanical actuation
Symbols

p3_1_3_12.ct
Didactics material < Basics and working principles < Symbols < Circuit symbol for pressure valves
Didactics material
Basics and working principles
Didactics material
Pressure valves are represented using squares. The flow direction is indicated by an arrow. The valve ports can be designated as P (supply port) and T (tank return port) or as A and B. The position of the arrow within the square indicates whether the valve is normally open or normally closed. Adjustable pressure valves are indicated by a diagonal arrow through the spring. Pressure valves are divided into pressure relief valves and pressure regulators.      
[22]  Circuit symbol for pressure valves
Circuit symbol for pressure valves
Symbols

p3_1_3_13.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for flow control valves
Didactics material
Basics and working principles
Didactics material
A distinction is made in flow control valves between types which are affected by viscosity and those which are unaffected. Flow control valves unaffected by viscosity are termed orifices. A 2-way flow control valve consists of restrictors, one adjustable restrictor which is unaffected by viscosity (orifice) and a regulating restrictor (pressure compensator). These valves are represented by a rectangle containing the symbol for the adjustable restrictor and an arrow to represent the pressure compensator. The diagonal arrow through the rectangle indicates that the valve is adjustable.      
[23]  Circuit symbols for flow control valves
Circuit symbols for flow control valves
Symbols

p3_1_3_14.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for non-return valves
Didactics material
Basics and working principles
Didactics material
The symbol for non-return valves is a ball which is pressed against a seat. Delockable non-return valves are shown by a square containing the symbol for a non- return valve. The pilot control for unlocking the non- return valve is indicated by a broken line at the pilot port. The pilot port is designated by the letter X.      
[24]  Circuit symbols for non-return valves
Circuit symbols for non-return valves
Symbols

p3_1_3_15.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for measuring devices
Didactics material
Basics and working principles
Didactics material
The illustration shows the symbols for measuring devices used in hydraulics.      
[25]  Circuit symbols for measuring devices
Circuit symbols for measuring devices
Symbols

p3_1_3_2.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for energy transfer (2)
Didactics material
Basics and working principles
Didactics material
The direction of the arrows in the circuit symbols for the heater and cooler correspond to the direction of heat flow.      
[12]  Circuit symbols for energy transfer (2)
Circuit symbols for energy transfer (2)
Symbols

p3_1_3_3.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for energy conversion
Didactics material
Basics and working principles
Didactics material
Hydraulic pumps are shown by a circle with a part representation of a drive shaft. Triangles in the circles show the direction of flow. The triangles are shown solid, since pressure fluid is used in hydraulics.      If the pressure medium is gaseous, as in the case of pneumatics, the triangles are shown in outline.  
[13]  Circuit symbols for energy conversion
Circuit symbols for energy conversion
Symbols

p3_1_3_4.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for hydraulic motors
Didactics material
Basics and working principles
Didactics material
The symbols for hydraulic motors are distinguished from the symbols for hydraulic pumps by the fact that the arrows showing the direction of flow are the other way round.      
[14]  Circuit symbols for hydraulic motors
Circuit symbols for hydraulic motors
Symbols

p3_1_3_5.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for single acting cylinders
Didactics material
Basics and working principles
Didactics material
Single acting cylinders have one port, i.e. pressure fluid can be applied only to the piston side. With these cylinders, the return stroke is produced either by external force, shown in the symbol by an opening bearing cap, or by a spring is shown within the symbol in this latter case.      
[15]  Circuit symbols for single acting cylinders
Circuit symbols for single acting cylinders
Symbols

p3_1_3_6.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for double acting cylinders
Didactics material
Basics and working principles
Didactics material
Double acting cylinders have two ports to allow pressure fluid to be applied to both cylinder chambers. The symbol for a differential cylinder is distinguished from the symbol for a double acting cylinder by the two lines added to the end of the piston rod. The area ratio is generally 2:1. In the case of cylinders with double- ended piston rods, the symbol shows that the piston areas are of equal size (synchronous cylinders).      
[16]  Circuit symbols for double acting cylinders
Circuit symbols for double acting cylinders
Symbols

p3_1_3_7.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for directional control valves (1)
Didactics material
Basics and working principles
Didactics material
Designations for directional control valves always give firstly the number of ports and then the number of switching positions. Directional control valves always have at least two ports and at least two switching positions. The number of squares shows the number of possible switching positions of a valve. Arrows within the squares show the direction of flow. Lines shown how the ports are interconnected in the various switching positions of the valve. The designations always relate to the normal position of the valve.      
[17]  Circuit symbols for directional control valves (1)
Circuit symbols for directional control valves (1)
Symbols

p3_1_3_8.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for directional control valves (2)
Didactics material
Basics and working principles
Didactics material
This illustration shows the circuit symbols for 4/2- and 5/2-way valves.      There are two general methods for the designation of ports, using either the letters P, T, R, A, B and L or consecutively using A, B, C, D etc.; the first method is the preferred one in the relevant standard.  
[18]  Circuit symbols for directional control valves (2)
Circuit symbols for directional control valves (2)
Symbols

p3_1_3_9.ct
Didactics material < Basics and working principles < Symbols < Circuit symbols for directional control valves (3)
Didactics material
Basics and working principles
Didactics material
The illustration shows the circuit symbols for 4/3-way valves with various mid-positions.      
[19]  Circuit symbols for directional control valves (3)
Circuit symbols for directional control valves (3)
Symbols

p3_1_4.ct
Didactics material < Basics and working principles < Some Physical Fundamentals
Didactics material
Basics and working principles
Didactics material
Some Physical Fundamentals
Some Physical Fundamentals
Hydrostatic pressure
Pressure propagation
Power transmission
Displacement transmission (1)
Displacement transmission (2)
Pressure transfer (1)
Pressure transfer (2)
Types of flow
Diesel effect 
Cavitation
Cavitation 
Input and output power

p3_1_4_1.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Hydrostatic pressure
Didactics material
Basics and working principles
Didactics material
Hydrostatic pressure is the pressure created above a certain level within a liquid as a result of the weight of the liquid mass. Hydrostatic pressure is not dependent on the shape of the vessel concerned but only on the height and density of the column of liquid.      Hydrostatic pressure can generally be ignored for the purpose of studying hydraulics (exception: see topic 2 p3_1_1_2).  
[26]  Hydrostatic pressure
Hydrostatic pressure
Some Physical Fundamentals

p3_1_4_10.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Cavitation
Didactics material
Basics and working principles
Didactics material
Motion energy is required for an increase in the flow velocity of the oil at a restriction. This motion energy is derived from the pressure energy. If the vacuum which results is smaller than -30 kPa (-0.3 bar), air dissolved in the oil is precipitated out. When the pressure rises again due to a reduction in speed, the oil bursts into the gas bubbles.      Cavitation is a significant factor in hydraulic systems as a cause of wear in devices and connections.  
[35]  Cavitation
Cavitation
Some Physical Fundamentals

p3_1_4_11.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Cavitation 
Didactics material
Basics and working principles
Didactics material
Local pressure peaks occur during cavitation. This causes the erosion of small particles from the wall of the pipe immediately after the reduced cross-section, leading to material fatigue and often also to fractures. This effect is accompanied by considerable noise.      
[36]  Cavitation
Cavitation 
Some Physical Fundamentals

p3_1_4_12.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Input and output power
Didactics material
Basics and working principles
Didactics material
Various losses occur at the individual devices within a hydraulic control chain. These consist essentially of mechanical, electrical and volumetric losses.      After an installation has been in service for some time, there will be a change in particular in the volumetric efficiency of the pump, as the result, for example, of cavitation (see topic 35 p3_1_4_10).  
[37]  Input and output power
Input and output power
Some Physical Fundamentals

p3_1_4_2.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Pressure propagation
Didactics material
Basics and working principles
Didactics material
If a force F acts on an area A of an enclosed liquid, a pressure p is produced which acts throughout the liquid (Pascal's Law).      Hydrostatic pressure has been ignored here. The term pressure propagation is also used to mean the pulse velocity in liquids (approx. 1000 m/s).  
[27]  Pressure propagation
Pressure propagation
Some Physical Fundamentals

p3_1_4_3.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Power transmission
Didactics material
Basics and working principles
Didactics material
If a force F1 is applied to an area A1 of a liquid, a pressure p results. If, as in this case, the pressure acts on a larger surface A2, then a larger counter-force F2 must be maintained. If A2 is three times as large as A1, then F2 will also be three times as large as F1.      Hydraulic power transmission is comparable to the mechanical law of levers.  
[28]  Power transmission
Power transmission
Some Physical Fundamentals

p3_1_4_4.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Displacement transmission (1)
Didactics material
Basics and working principles
Didactics material
If the input piston of the hydraulic press travels a distance s1, a volume of fluid will be displaced. This same volume displaces the output piston by the distance s2. If the area of this piston is larger than that of the input piston, the distance s2 will be shorter than s1.      Hydraulic displacement transmission is comparable to the mechanical law of levers.  
[29]  Displacement transmission (1)
Displacement transmission (1)
Some Physical Fundamentals

p3_1_4_5.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Displacement transmission (2)
Didactics material
Basics and working principles
Didactics material
See topic 29 p3_1_4_4      
[30]  Displacement transmission (2)
Displacement transmission (2)
Some Physical Fundamentals

p3_1_4_6.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Pressure transfer (1)
Didactics material
Basics and working principles
Didactics material
The fluid pressure p1 exerts a force F1 on the surface A1 which is transferred via the piston rod to the small piston. The force F1 thus acts on the surface A2 and produces the fluid pressure p2 . Since the piston area A2 is smaller than the piston area A1, the pressure p2 must be larger than the pressure p1.       The pressure-transfer (pressure-intensification) effect is put to practical use in pneumatic/hydraulic pressure intensifiers and also in purely hydraulic systems when extremely high pressures are required which a pump cannot deliver.  
[31]  Pressure transfer (1)
Pressure transfer (1)
Some Physical Fundamentals

p3_1_4_7.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Pressure transfer (2)
Didactics material
Basics and working principles
Didactics material
A pressure-transfer effect also occurs in conventional double acting cylinders with single piston rod.      This effect also causes problems in hydraulics. If, for example, an exhaust flow control is fitted to a differential cylinder for the advance stroke, a pressure- intensification effect results in the piston-rod chamber.  
[32]  Pressure transfer (2)
Pressure transfer (2)
Some Physical Fundamentals

p3_1_4_8.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Types of flow
Didactics material
Basics and working principles
Didactics material
A distinction is made between laminar flow and turbulent flow. In the case of laminar flow, the hydraulic fluid moves through the pipe in ordered cylindrical layers. If the flow velocity of the hydraulic fluid rises above a critical speed, the fluid particles at the center of the pipe break away to the side, and turbulence results.       Turbulent flow should be avoided in hydraulic circuits by ensuring they are adequate sized.  
[33]  Types of flow
Types of flow
Some Physical Fundamentals

p3_1_4_9.ct
Didactics material < Basics and working principles < Some Physical Fundamentals < Diesel effect 
Didactics material
Basics and working principles
Didactics material
A pressure drop to the level of vacuum may occur at points of restriction, causing precipitation of the air dissolved in the oil. When the pressure rises again, oil bursts into the gas bubbles and spontaneous ignition of the oil/air mixture may occur.      
[34]  Diesel effect
Diesel effect 
Some Physical Fundamentals

p3_1_5.ct
Didactics material < Basics and working principles < Components of a Power Unit
Didactics material
Basics and working principles
Didactics material
Components of a Power Unit
Components of a Power Unit
Hydraulic power unit
Hydraulic power unit: Reservoir
Externally toothed gear pump
Internally toothed gear pump 
Circuit diagram: Return flow filter
Circuit diagram : Pump inlet filter
Circuit diagram: Pressure line filter
Circuit diagram: Contamination indicator
Water cooler
Air cooler
Heating element
Circuit diagram: Hydraulic power unit

p3_1_5_1.ct
Didactics material < Basics and working principles < Components of a Power Unit < Hydraulic power unit
Didactics material
Basics and working principles
Didactics material
The hydraulic power unit (power supply unit) provides the energy required for the hydraulic installation. Its most important components are the reservoir (tank) , drive (electric motor), hydraulic pump, pressure relief valve (safety valve), filter and cooler. The hydraulic power unit may also act as a carrier for other devices (gauges, directional control valves).      
[38]  Hydraulic power unit
Hydraulic power unit
Components of a Power Unit

p3_1_5_10.ct
Didactics material < Basics and working principles < Components of a Power Unit < Air cooler
Didactics material
Basics and working principles
Didactics material
Hydraulic fluid from the return line flows through a coiled pipe which is cooled by a fan.      The advantages here are simplicity of installation and low operating costs. The noise of the fan may be a nuisance (see also topic 46 p3_1_5_9).  
[47]  Air cooler
Air cooler
Components of a Power Unit

p3_1_5_11.ct
Didactics material < Basics and working principles < Components of a Power Unit < Heating element
Didactics material
Basics and working principles
Didactics material
Heaters are often required to ensure that the optimum operating temperature is reached quickly. Heating elements or flow preheaters are used for heating and pre-heating hydraulic fluid.      If the viscosity is to high, the resulting increase in friction and cavitation leads to greater wear.  
[48]  Heating element
Heating element
Components of a Power Unit

p3_1_5_12.ct
Didactics material < Basics and working principles < Components of a Power Unit < Circuit diagram: Hydraulic power unit
Didactics material
Basics and working principles
Didactics material
The illustration shows the detailed circuit symbol for a hydraulic power unit.      Since this is an combination unit, a dot/dash line is placed around the symbols representing the individual units.  
[49]  Circuit diagram: Hydraulic power unit
Circuit diagram: Hydraulic power unit
Components of a Power Unit

p3_1_5_2.ct
Didactics material < Basics and working principles < Components of a Power Unit < Hydraulic power unit: Reservoir
Didactics material
Basics and working principles
Didactics material
The hydraulic reservoir contains the hydraulic fluid required the operate the installation. Within the reservoir, air, water and solid matter are separated out of the hydraulic fluid.      The size of the reservoir will depend on the practical application involved; for stationary systems, the volume of fluid delivered by the pump in 3 to 5 minutes can be taken as a guide. In mobile hydraulic systems, on the other hand, the reservoir contains only the maximum quantity of hydraulic fluid required.  
[39]  Hydraulic power unit: Reservoir
Hydraulic power unit: Reservoir
Components of a Power Unit

p3_1_5_3.ct
Didactics material < Basics and working principles < Components of a Power Unit < Externally toothed gear pump
Didactics material
Basics and working principles
Didactics material
The increase in volume which results when a tooth moves out of mesh produces a vacuum in the suction area. The hydraulic fluid is conveyed into the pressure area. The hydraulic fluid is then forced out of the tooth gaps by the meshing of the teeth and displaced into the above supply line.      
[40]  Externally toothed gear pump
Externally toothed gear pump
Components of a Power Unit

p3_1_5_4.ct
Didactics material < Basics and working principles < Components of a Power Unit < Internally toothed gear pump 
Didactics material
Basics and working principles
Didactics material
The inner gear is driven by a motor. The teeth of the inner wheel drive the outer gear wheel. The rotary motion creates a vacuum in the gaps between the teeth, causing hydraulic fluid to be sucked in. On the other side, the teeth engage once more and oil is displaced from the tooth chambers.      The design can deliver pressures of up to approx. 17.5 MPa (175 bar). Hydraulic motors represent the reverse of the function principle.  
[41]  Internally toothed gear pump
Internally toothed gear pump 
Components of a Power Unit

p3_1_5_5.ct
Didactics material < Basics and working principles < Components of a Power Unit < Circuit diagram: Return flow filter
Didactics material
Basics and working principles
Didactics material
An oil filter situated in the return line to the tank has the advantage that the filter is thus easy to maintain. A disadvantage, however, is that contamination is removed from the hydraulic fluid only after it has passed through the hydraulic components.      This configuration is often used.  
[42]  Circuit diagram: Return flow filter
Circuit diagram: Return flow filter
Components of a Power Unit

p3_1_5_6.ct
Didactics material < Basics and working principles < Components of a Power Unit < Circuit diagram : Pump inlet filter
Didactics material
Basics and working principles
Didactics material
With this configuration, the pump is protected from contamination. The filter is, on the other hand, less easily accessible.      If these filters have a too fine mesh, suction problems and cavitation effects may occur. Additional coarse filters upstream of the pump are recommended.  
[43]  Circuit diagram : Pump inlet filter
Circuit diagram : Pump inlet filter
Components of a Power Unit

p3_1_5_7.ct
Didactics material < Basics and working principles < Components of a Power Unit < Circuit diagram: Pressure line filter
Didactics material
Basics and working principles
Didactics material
Pressure filters can be installed selectively upstream of valves which are sensitive to contamination; this also enables smaller mesh sizes to be used.      A pressure-resistant housing is required, which makes this configuration more expensive.  
[44]  Circuit diagram: Pressure line filter
Circuit diagram: Pressure line filter
Components of a Power Unit

p3_1_5_8.ct
Didactics material < Basics and working principles < Components of a Power Unit < Circuit diagram: Contamination indicator
Didactics material
Basics and working principles
Didactics material
It is important that the effectiveness of a filter can be checked by a contamination indicator. The contamination of a filter is measured by the pressure drop; as the contamination increases, the pressure upstream of the filter increases. The pressure acts on a spring- loaded piston. As the pressure increases, the piston is pushed against a spring.      There are a number of different display methods. Either the piston movement is directly visible or it is converted into an electrical or visual indication by electrical contacts.  
[45]  Circuit diagram: Contamination indicator
Circuit diagram: Contamination indicator
Components of a Power Unit

p3_1_5_9.ct
Didactics material < Basics and working principles < Components of a Power Unit < Water cooler
Didactics material
Basics and working principles
Didactics material
With this design of cooler, hydraulic fluid is fed through tubes over which coolant (water) flows. The heat which is discharged can be re-used.      The operating temperature in hydraulic installations should not exceed 50 - 60ºC, since this would cause an unacceptable reduction in viscosity, leading to premature aging of the fluid. In comparison with air cooling, operating costs a higher due to the required coolant and the susceptibility to corrosion. Temperature difference of up to approx. 35ºC can be handled.  
[46]  Water cooler
Water cooler
Components of a Power Unit

p3_1_6.ct
Didactics material < Basics and working principles < Fundamentals of Valves
Didactics material
Basics and working principles
Didactics material
Fundamentals of Valves
Fundamentals of Valves
Actuating force
Poppet principle
Slide principle
Poppet valves
Piston overlap
Negative switching overlap
Positive switching overlap
Control edges
Vertical interconnection system

p3_1_6_1.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Actuating force
Didactics material
Basics and working principles
Didactics material
With some types of poppet valves, the actuating force, which is dependent on pressure and area, may be very high. In order to avoid this, pressure compensation may be provided at the valves.      
[50]  Actuating force
Actuating force
Fundamentals of Valves

p3_1_6_2.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Poppet principle
Didactics material
Basics and working principles
Didactics material
Valves are based either on the poppet principle or slide principle. In poppet valves, a ball, a cone or a disc is pressed by a spring against the seat of a passage. The high pressure per unit area which is created, means that valves of this kind provide a very efficient seal. The illustration shows a cone used as a sealing element.      
[51]  Poppet principle
Poppet principle
Fundamentals of Valves

p3_1_6_3.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Slide principle
Didactics material
Basics and working principles
Didactics material
This illustration shows the principle of a longitudinal slide valve. In order to allow the piston to move, it has a certain clearance and floats in hydraulic fluids. Ring grooves ensure an even film of oil and thus pressure equilibrium. The piston can thus be moved with minimal frictional losses.      This type of valve cannot provide a perfect seal, which means that there is always a certain oil leakage.  
[52]  Slide principle
Slide principle
Fundamentals of Valves

p3_1_6_4.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Poppet valves
Didactics material
Basics and working principles
Didactics material
In poppet valves, a ball, cone or occasionally a disk is pressed against a seat area to act as a sealing element. Valves of this type provide a very efficient seal.      
[53]  Poppet valves
Poppet valves
Fundamentals of Valves

p3_1_6_5.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Piston overlap
Didactics material
Basics and working principles
Didactics material
The switching characteristics of a valve are governed by, among other things, its piston overlap. A distinction is made between positive, negative and zero overlap. In the case of positive overlap, the port in question is completely covered by the piston, while with negative overlap it is less than completely covered. In the case of zero overlap, the distances between the control edges of the piston and of the port are exactly the same.      The individual control edges of the pilot piston can have different overlaps.  
[54]  Piston overlap
Piston overlap
Fundamentals of Valves

p3_1_6_6.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Negative switching overlap
Didactics material
Basics and working principles
Didactics material
In the case of negative overlap, flow from A to T is not quite closed when the inlet P is opened. This means that the pressure at port A rises slowly and the piston starts gently.      In manufacturers' data sheets, overlap positions are shown within dotted lines between the switching positions, or the overlap positions are shown in color or with a patterned background.  
[55]  Negative switching overlap
Negative switching overlap
Fundamentals of Valves

p3_1_6_7.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Positive switching overlap
Didactics material
Basics and working principles
Didactics material
In the case of positive overlap, the left-hand piston does not open the passage from P to A until the tank has been completely isolated by the other piston. Pressure is immediately fed to the load device (cylinder or hydraulic motor) with the result that this starts abruptly.      
[56]  Positive switching overlap
Positive switching overlap
Fundamentals of Valves

p3_1_6_8.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Control edges
Didactics material
Basics and working principles
Didactics material
The control edges of the pistons are often either sharp, chamfered or notched. The profiling of the control edges means that the throttling action of the flow when switching is gradual rather than abrupt.      See also the example in topic 144 p3_1_10_5.  
[57]  Control edges
Control edges
Fundamentals of Valves

p3_1_6_9.ct
Didactics material < Basics and working principles < Fundamentals of Valves < Vertical interconnection system
Didactics material
Basics and working principles
Didactics material
Vertical interconnection systems (“modular hydraulics”) mean that less space is required and that no piping is needed between the components. The circuit symbols directly marked on the components give greater clarity in the installation.      
[58]  Vertical interconnection system
Vertical interconnection system
Fundamentals of Valves

p3_1_7.ct
Didactics material < Basics and working principles < Pressure Valves
Didactics material
Basics and working principles
Didactics material
Pressure Valves
Pressure Valves
Pressure relief valve (1)
Pressure relief valve (2)
PRV used to limit system pressure
Circuit diagram: PRV used to limit system pressure
Circuit without brake valve 
Circuit diagram: Brake valve
Circuit with brake valve 
Circuit diagram: PRV as back-pressure valve
PRV, internally controlled, cushioned
PRV, externally controlled (1)
PRV, externally controlled (2)
Sequence valve
Circuit diagram: Sequence valve
Pressure relief valve
2-way pressure regulator (1)
2-way pressure regulator (2)
2-way pressure regulator (3)
2-way pressure regulator (4)
2-way pressure regulator (5)
Circuit diagram: 2-way pressure regulator
Circuit diagram: 2-way pressure regulator
3-way pressure regulator (1)
3-way pressure regulator (2)
3-way pressure regulator (3)
3-way pressure regulator (4)
3-way pressure regulator 
3-way pressure regulator (5)
3-way pressure regulator (6)
Circuit diagram: 3-way pressure regulator

p3_1_7_1.ct
Didactics material < Basics and working principles < Pressure Valves < Pressure relief valve (1)
Didactics material
Basics and working principles
Didactics material
In this design incorporating a poppet valve, a seal is pressed against the inlet port P by a pressure spring when the valve is in its normal position.      In this situation, for example, an unloaded piston rod is executing an advance stroke and the entire pump delivery is flowing to the cylinder.  
[59]  Pressure relief valve (1)
Pressure relief valve (1)
Pressure Valves

p3_1_7_10.ct
Didactics material < Basics and working principles < Pressure Valves < PRV, externally controlled (1)
Didactics material
Basics and working principles
Didactics material
This pressure relief valve controls the flow in accordance with an external pressure setting. This pressure acts against an adjustable spring force. The passage from the supply port P to the tank port T remains closed as long as no load acts on the pilot piston.      
[68]  PRV, externally controlled (1)
PRV, externally controlled (1)
Pressure Valves

p3_1_7_11.ct
Didactics material < Basics and working principles < Pressure Valves < PRV, externally controlled (2)
Didactics material
Basics and working principles
Didactics material
Pressure can be fed to the pilot piston via the pilot port X. As soon as the pressure force at the pilot piston exceeds the preset spring force, the pilot piston is displaced, allowing free flow.      
[69]  PRV, externally controlled (2)
PRV, externally controlled (2)
Pressure Valves

p3_1_7_12.ct
Didactics material < Basics and working principles < Pressure Valves < Sequence valve
Didactics material
Basics and working principles
Didactics material
The example shows a circuit with a pressure relief valve used as a pressure sequence valve. The pressure at the pilot piston of the PRV rises via the pressure regulator. The PRV opens and the high-pressure pump delivers directly to the tank. As soon as the 2/2-way valve opens, the pressure drops. The pressure relief valve closes and the high pressure pump is connected to the system.      
[70]  Sequence valve
Sequence valve
Pressure Valves

p3_1_7_13.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: Sequence valve
Didactics material
Basics and working principles
Didactics material
This illustration shows the same circuit as the previous illustration p3_1_7_12, but with the cut-away view of the sequence valve replaced by the appropriate circuit symbol.      
[71]  Circuit diagram: Sequence valve
Circuit diagram: Sequence valve
Pressure Valves

p3_1_7_14.ct
Didactics material < Basics and working principles < Pressure Valves < Pressure relief valve
Didactics material
Basics and working principles
Didactics material
Actual photograph of a pressure relief valve.      
[72]  Pressure relief valve
Pressure relief valve
Pressure Valves

p3_1_7_15.ct
Didactics material < Basics and working principles < Pressure Valves < 2-way pressure regulator (1)
Didactics material
Basics and working principles
Didactics material
This valve is normally open. The outlet pressure (A) acts via a pilot line on the left-hand surface of the pilot piston against an adjustable spring force.      Pressure regulators reduce the inlet pressure to an adjustable outlet pressure. It is appropriate to use these in hydraulic installations only if different pressures are required.  
[73]  2-way pressure regulator (1)
2-way pressure regulator (1)
Pressure Valves

p3_1_7_16.ct
Didactics material < Basics and working principles < Pressure Valves < 2-way pressure regulator (2)
Didactics material
Basics and working principles
Didactics material
When the pressure rises at outlet A, the force at the left-hand surface of the pilot piston becomes greater, the piston is displaced to the right and the throttle gap becomes narrower. This causes a pressure drop.      In the case of slide valves, it is also possible to design the control edges in such way that the opening gap increases only slowly. This gives greater control precision.  
[74]  2-way pressure regulator (2)
2-way pressure regulator (2)
Pressure Valves

p3_1_7_17.ct
Didactics material < Basics and working principles < Pressure Valves < 2-way pressure regulator (3)
Didactics material
Basics and working principles
Didactics material
When the preset maximum pressure is reached, the throttle point closes completely; the pressure set on the pressure relief valve is produced at the inlet P.      
[75]  2-way pressure regulator (3)
2-way pressure regulator (3)
Pressure Valves

p3_1_7_18.ct
Didactics material < Basics and working principles < Pressure Valves < 2-way pressure regulator (4)
Didactics material
Basics and working principles
Didactics material
In the circuit illustrated, the piston rod of the cylinder is executing an advance stroke. The pressure at the outlet A of the pressure regulator is less than the system pressure at P and constant.      
[76]  2-way pressure regulator (4)
2-way pressure regulator (4)
Pressure Valves

p3_1_7_19.ct
Didactics material < Basics and working principles < Pressure Valves < 2-way pressure regulator (5)
Didactics material
Basics and working principles
Didactics material
The piston rod of the cylinder is now in its forward end position. The pressure at outlet A thus continues to rise and the throttle point closes completely.      
[77]  2-way pressure regulator (5)
2-way pressure regulator (5)
Pressure Valves

p3_1_7_2.ct
Didactics material < Basics and working principles < Pressure Valves < Pressure relief valve (2)
Didactics material
Basics and working principles
Didactics material
As soon as the force exerted by the inlet pressure at A exceeds the opposing spring force, the valve begins to open.      In this situation, for example, the piston rod is fully advanced; the entire pump delivery is flowing at the preset system pressure to the tank.  
[60]  Pressure relief valve (2)
Pressure relief valve (2)
Pressure Valves

p3_1_7_20.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: 2-way pressure regulator
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration, but with the 2-way pressure regulator in the form of a circuit symbol.      
[78]  Circuit diagram: 2-way pressure regulator
Circuit diagram: 2-way pressure regulator
Pressure Valves

p3_1_7_21.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: 2-way pressure regulator
Didactics material
Basics and working principles
Didactics material
It is appropriate to use PRVs only when different pressures are required in an installation. The mod of operation of pressure regulator will thus be explained here by taking an example with two control circuits. The first control circuit acts via a flow control valve on a hydraulic motor which drives a roller. This roller is used to stick together multi-layered printed circuit boards. The second control circuit acts on a hydraulic cylinder which draws the roller towards the boards at an adjustable reduced pressure.      This example can be used as a preliminary stage to the introduction of the 3-way PR. If the 2-way PR is closed due to the fact that the preset maximum pressure has been reached, thickening of the material of the workpieces would cause an increase in the pressure on the outlet side of the PR to a higher value than desired. (See also the animation for topic 84 p3_1_7_26.)  
[79]  Circuit diagram: 2-way pressure regulator
Circuit diagram: 2-way pressure regulator
Pressure Valves

p3_1_7_22.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator (1)
Didactics material
Basics and working principles
Didactics material
The 3-way pressure regulator can be regarded as a combination of a 2-way PR and a pressure relief valve (PRV). The PR is in its normal position here; only a low pressure has built up at the outlet A.      
[80]  3-way pressure regulator (1)
3-way pressure regulator (1)
Pressure Valves

p3_1_7_23.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator (2)
Didactics material
Basics and working principles
Didactics material
When the pressure at A rises the result of external conditions, this pressure acts via a pilot line on the left-hand piston surface of the pilot piston against an adjustable spring force. Every pressure increase causes the throttle gap to become narrower, resulting in a pressure drop.      
[81]  3-way pressure regulator (2)
3-way pressure regulator (2)
Pressure Valves

p3_1_7_24.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator (3)
Didactics material
Basics and working principles
Didactics material
When the maximum preset pressure is reached, the throttle point closes completely. The pressure set on the system-pressure limiter is produced at the inlet P.      
[82]  3-way pressure regulator (3)
3-way pressure regulator (3)
Pressure Valves

p3_1_7_25.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator (4)
Didactics material
Basics and working principles
Didactics material
If the pressure rises above the preset value as the result of an external load at outlet A, the valve opens to allow flow from A to the tank port T (pressure-limiter function).      3-way pressure regulators are available with both positive and negative piston overlap. If a 3-way pressure regulator is created by combining a 2-way pressure regulator and a pressure relief valve, the “overlap” is adjustable.  
[83]  3-way pressure regulator (4)
3-way pressure regulator (4)
Pressure Valves

p3_1_7_26.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator 
Didactics material
Basics and working principles
Didactics material
The animation shows both the pressure-regulator and pressure-limiter function of a 3-way pressure regulator through the example of a roller which exerts a constant pressure on moving material of variable thickness.      The final control element which is normally interposed has been omitted here in the interests of clarity.  
[84]  3-way pressure regulator
3-way pressure regulator 
Pressure Valves

p3_1_7_27.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator (5)
Didactics material
Basics and working principles
Didactics material
A 3-way PR is shown here in a functional representation, incorporated into a model circuit diagram. The piston rod of the cylinder is subject to external force and the pressure regulator provides a pressure-limiter function.      
[85]  3-way pressure regulator (5)
3-way pressure regulator (5)
Pressure Valves

p3_1_7_28.ct
Didactics material < Basics and working principles < Pressure Valves < 3-way pressure regulator (6)
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_7_27, but with the functional representation of the 3-way pressure regulator replaced by a “detailed” circuit symbol.      3-way pressure regulators are available with both positive and negative piston overlap. If a 3-way pressure regulator is created by combining a 2-way pressure regulator and a pressure relief valve, the “overlap” is adjustable.  
[86]  3-way pressure regulator (6)
3-way pressure regulator (6)
Pressure Valves

p3_1_7_29.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: 3-way pressure regulator
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_7_28, but with the standard circuit symbol for a 3-way pressure regulator.      
[87]  Circuit diagram: 3-way pressure regulator
Circuit diagram: 3-way pressure regulator
Pressure Valves

p3_1_7_3.ct
Didactics material < Basics and working principles < Pressure Valves < PRV used to limit system pressure
Didactics material
Basics and working principles
Didactics material
This illustration shows a pressure relief valve within a basic hydraulic circuit (used to control a double acting cylinder).      The resistances at the outlet (tank line, filter) must be added to the force of the spring in the pressure relief valve. See also the animation “Interaction of components” (topic 7) p3_1_2_4.  
[61]  PRV used to limit system pressure
PRV used to limit system pressure
Pressure Valves

p3_1_7_4.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: PRV used to limit system pressure
Didactics material
Basics and working principles
Didactics material
This illustration shows the same circuit as the previous illustration, but with the cut-away view of the PRV replaced by the appropriate circuit symbol.      
[62]  Circuit diagram: PRV used to limit system pressure
Circuit diagram: PRV used to limit system pressure
Pressure Valves

p3_1_7_5.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit without brake valve 
Didactics material
Basics and working principles
Didactics material
One application of pressure relief valves is as brake valves; these prevent pressure peaks which may otherwise occur as the result of mass moments of inertia when a directional control valve is suddenly closed. The animation shows an (incorrect) circuit in schematic form in which the working line on the exhaust side has fractured due to the absence of a brake valve.      The next animation (topic 64 p3_1_7_6) shows the correct circuit.  
[63]  Circuit without brake valve
Circuit without brake valve 
Pressure Valves

p3_1_7_6.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: Brake valve
Didactics material
Basics and working principles
Didactics material
This illustration shows the correct circuit for the problem in topic 63 p3_1_7_5. This circuit incorporates not only a brake valve on the piston-rod side but also a non-return valve on the inlet side via which oil can be taken in from a reservoir during the vacuum phase following the closure of the directional control valve.      The following animation p3_1_7_7 shows the events which occur in the two working lines.  
[64]  Circuit diagram: Brake valve
Circuit diagram: Brake valve
Pressure Valves

p3_1_7_7.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit with brake valve 
Didactics material
Basics and working principles
Didactics material
First the animation shows in schematic form the behavior of the PRV during the braking phase, then it shows the behavior of the non-return valve (NRV) in the supply line.      The necessity of the brake valve can be demonstrated by topic 63 p3_1_7_5.  
[65]  Circuit with brake valve
Circuit with brake valve 
Pressure Valves

p3_1_7_8.ct
Didactics material < Basics and working principles < Pressure Valves < Circuit diagram: PRV as back-pressure valve
Didactics material
Basics and working principles
Didactics material
Back-pressure valves counteract mass moments of inertia with tractive loads. The illustration shows a circuit with a back-pressure valve on the piston-rod side. On the return stroke, the PRV is by-passed by an NRV.      The PRV must be pressure-compensated and the tank port must be capable of carrying a pressure load.  
[66]  Circuit diagram: PRV as back-pressure valve
Circuit diagram: PRV as back-pressure valve
Pressure Valves

p3_1_7_9.ct
Didactics material < Basics and working principles < Pressure Valves < PRV, internally controlled, cushioned
Didactics material
Basics and working principles
Didactics material
Pressure relief valves often incorporate cushioning pistons or flow control valves. The cushioning device shown provides fast opening and slow closing of the valve. This prevents damage caused by pressure shocks (smooth valve operation).      Pressure shock arise, for example, when the pump delivers oil in an almost unpressurized condition and the supply port of the load device is abruptly closed by a directional control valve.  
[67]  PRV, internally controlled, cushioned
PRV, internally controlled, cushioned
Pressure Valves

p3_1_8.ct
Didactics material < Basics and working principles < Way Valves
Didactics material
Basics and working principles
Didactics material
Way Valves
Way Valves
2/2-way valve (1)
2/2-way valve (2)
2/2-way valve as by-pass valve
Circuit diagram: 2/2-way valve as by-pass valve
Circuit diagram: 2/2-way valve as final control element
2/2-way valve as final control element 
Circuit diagram for pressure-less pump recirculation
Circuit diagram: Pressure stage circuit
3/2-way valve (poppet principle) (1)
3/2-way valve (poppet principle) (2)
3/2-way valve as final control element
Circuit diagram: 3/2-way valve as final control element
3/2-way valve 
3/2-way valve (slide principle) (1)
3/2-way valve (slide principle) (2)
3/2-way valves as diverter
4/2-way valve, two pistons (1)
4/2-way valve, two pistons (2)
4/2-way valve, three pistons (1)
4/2-way valve, three pistons (2)
4/2-way valve, three pistons (3)
Circuit diagram: 4/2-way valve
4/3-way valve with pump bypass (1)
4/3-way valve with pump bypass (2)
4/3-way valve with pump bypass (3)
4/3-way valve with pump bypass (4)
Circuit diagram: 4/3-way valve with pump bypass
4/3-way valve with pump bypass 
4/3-way valve with closed mid-position (1)
4/3-way valve with closed mid-position (2)
4/3-way valve with closed mid-position (3)
4/3-way valve with closed mid-position (4)
Circuit diagram: 4/3-way valve with closed mid-position
4/3-way valve: overlap positions (1)
4/3-way valve: overlap positions (2)
Directional control valve
4/3-way module

p3_1_8_1.ct
Didactics material < Basics and working principles < Way Valves < 2/2-way valve (1)
Didactics material
Basics and working principles
Didactics material
The 2/2-way valve has a working port A, a supply port P and a leakage-oil port L. In the case of the valve shown here, of slide design, flow from P to A is closed in the normal position.      A relief line leading to the leakage-oil port is provided to prevent a build-up of pressure in the spring and piston chambers.  
[88]  2/2-way valve (1)
2/2-way valve (1)
Way Valves

p3_1_8_10.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valve (poppet principle) (2)
Didactics material
Basics and working principles
Didactics material
The 3/2-way valve is actuated; flow is released from P to A, the outlet T is closed.      3/2-way valves which are normally open from P to A and T closed are also available.  
[97]  3/2-way valve (poppet principle) (2)
3/2-way valve (poppet principle) (2)
Way Valves

p3_1_8_11.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valve as final control element
Didactics material
Basics and working principles
Didactics material
The circuit shows the 3/2-way valve in a functional representation as a final control element of a single acting cylinder.      The non-return valve protects the pump in cases where the 3/2-way valve is actuated and the piston rod is subject to an external load.  
[98]  3/2-way valve as final control element
3/2-way valve as final control element
Way Valves

p3_1_8_12.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: 3/2-way valve as final control element
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_8_11, but with the circuit symbol for the 3/2-way valve.      
[99]  Circuit diagram: 3/2-way valve as final control element
Circuit diagram: 3/2-way valve as final control element
Way Valves

p3_1_8_13.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valve 
Didactics material
Basics and working principles
Didactics material
The animations show the actuation and release of the manual pushbutton for a 3/2-way valve, which causes the piston rod of the cylinder to advance and retract.      
[100]  3/2-way valve
3/2-way valve 
Way Valves

p3_1_8_14.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valve (slide principle) (1)
Didactics material
Basics and working principles
Didactics material
The 3/2-way valve has a working port A, a supply port P and a tank port T. The volumetric flow can be routed from the supply port to the working port, or from the working port to the tank port. The third port in each case is closed. In the normal position shown, P is closed and flow is released from A to T.      See also the 3/2-way valve designed on the poppet principle (Topic 96 p3_1_8_9).  
[101]  3/2-way valve (slide principle) (1)
3/2-way valve (slide principle) (1)
Way Valves

p3_1_8_15.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valve (slide principle) (2)
Didactics material
Basics and working principles
Didactics material
The 3/2-way valve is actuated; flow is released from P to A, and the outlet T is closed.      3/2-way valves which are normally closed from P to A and T are also available.  
[102]  3/2-way valve (slide principle) (2)
3/2-way valve (slide principle) (2)
Way Valves

p3_1_8_16.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valves as diverter
Didactics material
Basics and working principles
Didactics material
In addition to their application as final control elements, 3/2-way valves can also be used as diverters. In this case, port T is connected to a further device, to which a switch-over can then be made. The part circuit diagrams show the facility to switch between the flow control valves with different settings and between heating and cooling.      The circuit symbol is drawn reversed to simplify the representation of the circuit diagram.  
[103]  3/2-way valves as diverter
3/2-way valves as diverter
Way Valves

p3_1_8_17.ct
Didactics material < Basics and working principles < Way Valves < 4/2-way valve, two pistons (1)
Didactics material
Basics and working principles
Didactics material
The 4/2-way valve has two working ports A and B, a supply port P and a tank port T. The supply port is always connected to one of the working ports, while the second working port is routed to the tank. In the normal position, there is flow from P to B and from A to T.      In contrast to valves with three pistons, 4/2-way valves with two pistons do not require a leakage-oil port (see topic 106 p3_1_8_19).  
[104]  4/2-way valve, two pistons (1)
4/2-way valve, two pistons (1)
Way Valves

p3_1_8_18.ct
Didactics material < Basics and working principles < Way Valves < 4/2-way valve, two pistons (2)
Didactics material
Basics and working principles
Didactics material
The 4/2-way valve is actuated, and there is flow from P to A and from B to T.      4/2-way valves are also available which are normally open from P to A and from B to T.  
[105]  4/2-way valve, two pistons (2)
4/2-way valve, two pistons (2)
Way Valves

p3_1_8_19.ct
Didactics material < Basics and working principles < Way Valves < 4/2-way valve, three pistons (1)
Didactics material
Basics and working principles
Didactics material
This 4/2-way valve has two working ports A and B, a supply port P and a tank port T. The supply port is always connected to one of the working ports, while the second working port is routed to the tank. In the neutral position, there is flow from P to B and from A to T.      4/2-way valves with three pistons require a leakage-oil port, since hydraulic fluid would otherwise be trapped within the valve.  
[106]  4/2-way valve, three pistons (1)
4/2-way valve, three pistons (1)
Way Valves

p3_1_8_2.ct
Didactics material < Basics and working principles < Way Valves < 2/2-way valve (2)
Didactics material
Basics and working principles
Didactics material
The 2/2-way valve is actuated and the passage from P to A is open.      2/2-way valves are also available which are normally open from P to A.  
[89]  2/2-way valve (2)
2/2-way valve (2)
Way Valves

p3_1_8_20.ct
Didactics material < Basics and working principles < Way Valves < 4/2-way valve, three pistons (2)
Didactics material
Basics and working principles
Didactics material
The 4/2-way valve is actuated, and there is flow from P to A and from B to T.      
[107]  4/2-way valve, three pistons (2)
4/2-way valve, three pistons (2)
Way Valves

p3_1_8_21.ct
Didactics material < Basics and working principles < Way Valves < 4/2-way valve, three pistons (3)
Didactics material
Basics and working principles
Didactics material
The circuit shows the 4/2-way valve in functional representation as a final control element of a double acting cylinder.      The non-return valve protects the pump in cases where the piston rod of the cylinder is subject to an external load.  
[108]  4/2-way valve, three pistons (3)
4/2-way valve, three pistons (3)
Way Valves

p3_1_8_22.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: 4/2-way valve
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_8_21, but with the 4/2-way valve as a circuit symbol.      
[109]  Circuit diagram: 4/2-way valve
Circuit diagram: 4/2-way valve
Way Valves

p3_1_8_23.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with pump bypass (1)
Didactics material
Basics and working principles
Didactics material
From the logic point of view, 4/3-way valves are 4/2- way valves with an additional mid-position. There are various versions of this mid-position (in the mid-position in the example shown, the supply port P is directly connected to the tank T, see next illustration p3_1_8_24). In the switching position shown, there is flow from P to B and from A to T.      4/3-way valves are easy to construct as slide valves and of complex design as poppet valves.  
[110]  4/3-way valve with pump bypass (1)
4/3-way valve with pump bypass (1)
Way Valves

p3_1_8_24.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with pump bypass (2)
Didactics material
Basics and working principles
Didactics material
The 4/3-way valve is in its mid-position; there is flow from P to T, while A and B are closed. Since the output from the pump flows to the tank, this switching position is called pump bypass or also pump recirculation.      In the case of pump bypass, the pump needs to operate only against the resistance of the valve, which has a favorable effect on the power balance.  
[111]  4/3-way valve with pump bypass (2)
4/3-way valve with pump bypass (2)
Way Valves

p3_1_8_25.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with pump bypass (3)
Didactics material
Basics and working principles
Didactics material
The valve is in its left-hand switching position; there is flow from P to A and from B to T.      
[112]  4/3-way valve with pump bypass (3)
4/3-way valve with pump bypass (3)
Way Valves

p3_1_8_26.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with pump bypass (4)
Didactics material
Basics and working principles
Didactics material
The circuit shows the 4/3-way valve in functional representation as a final control element of a double acting cylinder. The valve is in its mid-position; the pump delivery flows via the by-pass line within the pilot piston to the tank.      The non-return valve protects the pump in cases where the piston rod of the cylinder is subject to an external load.  
[113]  4/3-way valve with pump bypass (4)
4/3-way valve with pump bypass (4)
Way Valves

p3_1_8_27.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: 4/3-way valve with pump bypass
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_8_26, but with the 4/3-way valve as a circuit symbol.      
[114]  Circuit diagram: 4/3-way valve with pump bypass
Circuit diagram: 4/3-way valve with pump bypass
Way Valves

p3_1_8_28.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with pump bypass 
Didactics material
Basics and working principles
Didactics material
The animations show the switching of the 4/3-way valve into the three switching positions and the corresponding cylinder movements. During the advance stroke, movement can be halted by switching to the mid- position.      As appropriate to the application in question, a circuit of this kind must be equipped with a brake valve to prevent damage to the installation when the valve is switched to the mid-position (see also topic 64 p3_1_7_6).  
[115]  4/3-way valve with pump bypass
4/3-way valve with pump bypass 
Way Valves

p3_1_8_29.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with closed mid-position (1)
Didactics material
Basics and working principles
Didactics material
From the logic point of view, 4/3-way valves are 4/2- way valves with an additional mid-position. There are various versions of this mid-position (in the mid-position in the example shown, all ports are closed in the mid- position, see next illustration p3_1_8_30). In the switching position shown, there is flow from P to B and from A to T.      
[116]  4/3-way valve with closed mid-position (1)
4/3-way valve with closed mid-position (1)
Way Valves

p3_1_8_3.ct
Didactics material < Basics and working principles < Way Valves < 2/2-way valve as by-pass valve
Didactics material
Basics and working principles
Didactics material
This example shows a 2/2-way valve used as a by-pass valve; when the 2/2-way valve is actuated, the flow control valve 0V2 is by-passed, causing the piston rod of the cylinder to advance at maximum speed.      
[90]  2/2-way valve as by-pass valve
2/2-way valve as by-pass valve
Way Valves

p3_1_8_30.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with closed mid-position (2)
Didactics material
Basics and working principles
Didactics material
The 4/3-way valve is in its mid-position; all ports apart from the leakage-oil port are closed.      In this mid-position, the pump is operating against the system pressure set on the pressure relief valve.  
[117]  4/3-way valve with closed mid-position (2)
4/3-way valve with closed mid-position (2)
Way Valves

p3_1_8_31.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with closed mid-position (3)
Didactics material
Basics and working principles
Didactics material
The valve is in its left-hand switching position; there is flow from P to A and from B to T.      
[118]  4/3-way valve with closed mid-position (3)
4/3-way valve with closed mid-position (3)
Way Valves

p3_1_8_32.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve with closed mid-position (4)
Didactics material
Basics and working principles
Didactics material
The circuit shows the 4/3-way valve in functional representation as a final control element of a double acting cylinder. The valve is in its mid-position; the pump is operating against the system pressure set on the PRV.      If, with an operational installation, it is desired to switch to pump recirculation, this can be achieved by using an additional 2/2-way valve as a changeover valve (see part circuit-diagram in topic 94 p3_1_8_7).  
[119]  4/3-way valve with closed mid-position (4)
4/3-way valve with closed mid-position (4)
Way Valves

p3_1_8_33.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: 4/3-way valve with closed mid-position
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_8_32, but with the 4/3-way valve as a circuit symbol.      
[120]  Circuit diagram: 4/3-way valve with closed mid-position
Circuit diagram: 4/3-way valve with closed mid-position
Way Valves

p3_1_8_34.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve: overlap positions (1)
Didactics material
Basics and working principles
Didactics material
The illustration shows the left-hand overlap position of a 4/3-way valve with positive overlap in the mid-position (closed mid-position). This overlap position is a mixture of positive and negative overlap; P is connected to A, B and T are closed.      With 4/3-way valves, the types of overlap positions is generally specified in the data sheet.  
[121]  4/3-way valve: overlap positions (1)
4/3-way valve: overlap positions (1)
Way Valves

p3_1_8_35.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way valve: overlap positions (2)
Didactics material
Basics and working principles
Didactics material
The illustration shows the “right-hand” overlap position of a 4/3-way valve with positive overlap in the mid- position (closed mid-position). This overlap position, too, is a mixture of positive and negative overlap; P is connected to B, A and T are closed.      
[122]  4/3-way valve: overlap positions (2)
4/3-way valve: overlap positions (2)
Way Valves

p3_1_8_36.ct
Didactics material < Basics and working principles < Way Valves < Directional control valve
Didactics material
Basics and working principles
Didactics material
Actual photograph of a directional control valve with lever actuation.      
[123]  Directional control valve
Directional control valve
Way Valves

p3_1_8_37.ct
Didactics material < Basics and working principles < Way Valves < 4/3-way module
Didactics material
Basics and working principles
Didactics material
This 4/3-way module with hand-lever actuation is used in vertical interconnection systems (“modular hydraulics”).      See also the illustration in topic 58 p3_1_6_9.  
[124]  4/3-way module
4/3-way module
Way Valves

p3_1_8_4.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: 2/2-way valve as by-pass valve
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_8_3, but with the functional representation of the 2/2-way valve replaced by a circuit symbol.      
[91]  Circuit diagram: 2/2-way valve as by-pass valve
Circuit diagram: 2/2-way valve as by-pass valve
Way Valves

p3_1_8_5.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: 2/2-way valve as final control element
Didactics material
Basics and working principles
Didactics material
In its initial position, the cylinder is advanced. If the 2/2- way valve 0V1 is actuated, the entire volumetric flow passes to the tank and piston rod of the cylinder is reset by the external load m. If 0V1 is not actuated, the system pressure set on the pressure limiter 0V2 builds up and the piston rod advances.      In the initial position, the pump operates against the preset system pressure, which has an unfavorable effect on the power balance of the circuit shown.  
[92]  Circuit diagram: 2/2-way valve as final control element
Circuit diagram: 2/2-way valve as final control element
Way Valves

p3_1_8_6.ct
Didactics material < Basics and working principles < Way Valves < 2/2-way valve as final control element 
Didactics material
Basics and working principles
Didactics material
The animations show the actuation and release of the 2/2-way valve, which causes the piston rod of the cylinder to advance and retract.      
[93]  2/2-way valve as final control element
2/2-way valve as final control element 
Way Valves

p3_1_8_7.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram for pressure-less pump recirculation
Didactics material
Basics and working principles
Didactics material
The part circuit diagram shows a 2/2-way valve used as a by-pass valve to achieve pressure-less pump recirculation; if the valve is actuated, the pump no longer needs to operate against the preset system pressure.      One application of this circuit is with 4/3-way valves which are closed in their mid-position in cases where, with the installation operational, it is desired to switch to pump recirculation (see also topic 116 p3_1_8_29).  
[94]  Circuit diagram for pressure-less pump recirculation
Circuit diagram for pressure-less pump recirculation
Way Valves

p3_1_8_8.ct
Didactics material < Basics and working principles < Way Valves < Circuit diagram: Pressure stage circuit
Didactics material
Basics and working principles
Didactics material
The part circuit diagram shows a 2/2-way valve used as a selector switch for one of two preset system pressures (“pressure levels”); if the 2/2-way valve is actuated, flow is enabled to a second system-pressure limiter.      
[95]  Circuit diagram: Pressure stage circuit
Circuit diagram: Pressure stage circuit
Way Valves

p3_1_8_9.ct
Didactics material < Basics and working principles < Way Valves < 3/2-way valve (poppet principle) (1)
Didactics material
Basics and working principles
Didactics material
The 3/2-way valve has working port A, a supply port P and a tank port T. Volumetric flow can be routed from the supply port to the working port or from the working port to the tank port. The third port in each case is closed. In the normal position shown, P is closed and flow released from A to T.      See also topic 101 p3_1_8_14 (slide principle).  
[96]  3/2-way valve (poppet principle) (1)
3/2-way valve (poppet principle) (1)
Way Valves

p3_1_9.ct
Didactics material < Basics and working principles < Shutoff Valves
Didactics material
Basics and working principles
Didactics material
Shutoff Valves
Shutoff Valves
Non-return valve (1)
Non-return valve (2)
Circuit diagram: Pump protection
Graetz block (1)
Graetz block (2)
Graetz block 
Delockable non-return valve (1)
Delockable non-return valve (2)
Delockable non-return valve (3)
Circuit diagram: Delockable non-return valve
Delockable non-return valve 
Delockable double non-return valve (1)
Delockable double non-return valve (2)
Delockable double non-return valve (3)
Circuit diagram: Delockable double non-return valve

p3_1_9_1.ct
Didactics material < Basics and working principles < Shutoff Valves < Non-return valve (1)
Didactics material
Basics and working principles
Didactics material
Non-return valves block flow in one direction and allow free flow in the other. In the direction of flow shown, the sealing element is pressed against a seat by a spring and the hydraulic fluid.      These valves are also available in designs without springs. Since there must be no leaks in the closed position, these valves are generally of poppet design.  
[125]  Non-return valve (1)
Non-return valve (1)
Shutoff Valves

p3_1_9_10.ct
Didactics material < Basics and working principles < Shutoff Valves < Circuit diagram: Delockable non-return valve
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_9_9, but with the piloted non-return valve as a circuit symbol.      
[134]  Circuit diagram: Delockable non-return valve
Circuit diagram: Delockable non-return valve
Shutoff Valves

p3_1_9_11.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable non-return valve 
Didactics material
Basics and working principles
Didactics material
The 4/2-way valve is actuated, the hydraulic fluid passes through the non-return valve against the force of the return spring and the piston rod advances. When the 4/2-way valve is reset, the outlet on the piston side is closed by the non-return valve, and the cylinder remains advanced. The 3/2-way valve is now actuated, the pilot piston is reversed and the outlet flow released; the piston rod begins to retract. During the return stroke, the 3/2-way valve is brought temporarily into its normal position. This causes the outlet to be closed again, and the piston rod and load remain in their current position. When the 3/2-way valve is actuated again, the piston rod travels to its retracted end position.      
[135]  Delockable non-return valve
Delockable non-return valve 
Shutoff Valves

p3_1_9_12.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable double non-return valve (1)
Didactics material
Basics and working principles
Didactics material
Delockable double non-return valves allow a load to be positioned reliably with the cylinder at a standstill, even if eternal leaks exist around the cylinder piston. When, as in the case, neither of the inlets A1 or A2 is pressurized, B1 and B2 are closed.      
[136]  Delockable double non-return valve (1)
Delockable double non-return valve (1)
Shutoff Valves

p3_1_9_13.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable double non-return valve (2)
Didactics material
Basics and working principles
Didactics material
When A1 is pressurized, the left-hand sealing element is lifted from its seat, enabling flow to B1. At the same time, the pilot piston is displaced to the right, releasing flow from B2 to A2.      The opposite is true when inlet A_2 is pressurized.  
[137]  Delockable double non-return valve (2)
Delockable double non-return valve (2)
Shutoff Valves

p3_1_9_14.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable double non-return valve (3)
Didactics material
Basics and working principles
Didactics material
The model circuit diagram shows a delockable double non-return valve used in conjunction with a 4/3-way valve to allow the vertical positioning of a load. In the mid-position of the final control element shown, ports A and B are connected to the tank. This means that the inlets A1 and A2 of the double non-return valve are pressure-less and both cylinder supply lines are closed.      
[138]  Delockable double non-return valve (3)
Delockable double non-return valve (3)
Shutoff Valves

p3_1_9_15.ct
Didactics material < Basics and working principles < Shutoff Valves < Circuit diagram: Delockable double non-return valve
Didactics material
Basics and working principles
Didactics material
The illustration shows the same circuit as the previous illustration p3_1_9_14, but with the delockable double non-return valve as a circuit symbol.      
[139]  Circuit diagram: Delockable double non-return valve
Circuit diagram: Delockable double non-return valve
Shutoff Valves

p3_1_9_2.ct
Didactics material < Basics and working principles < Shutoff Valves < Non-return valve (2)
Didactics material
Basics and working principles
Didactics material
In the direction of flow shown, the valve is opened by the hydraulic fluid, which lifts the sealing element from the seat.      
[126]  Non-return valve (2)
Non-return valve (2)
Shutoff Valves

p3_1_9_3.ct
Didactics material < Basics and working principles < Shutoff Valves < Circuit diagram: Pump protection
Didactics material
Basics and working principles
Didactics material
In this circuit, the non-return valve is used to protect the pump. This prevents a load pressure from driving the pump in reverse when the electric motor is switched off. Pressure peaks do not affect the pump but are discharged via the pressure relief valve.      
[127]  Circuit diagram: Pump protection
Circuit diagram: Pump protection
Shutoff Valves

p3_1_9_4.ct
Didactics material < Basics and working principles < Shutoff Valves < Graetz block (1)
Didactics material
Basics and working principles
Didactics material
In the Graetz rectifier circuit (Graetz block), four non- return valves are combined to form a function unit. The circuit diagram shows how this operates in conjunction with a flow control valve; flow passes through this valve from left to right during both the advance and return strokes of the cylinder. The situation during the advance stroke is shown.      During the advance stroke shown here, flow control is carried out on the inlet side.  
[128]  Graetz block (1)
Graetz block (1)
Shutoff Valves

p3_1_9_5.ct
Didactics material < Basics and working principles < Shutoff Valves < Graetz block (2)
Didactics material
Basics and working principles
Didactics material
The cylinder is on its return stroke. The rectifier circuit means that flow once again passes through the flow control valve from left to right.      During the return stroke shown here, flow control is carried out on the outlet side.  
[129]  Graetz block (2)
Graetz block (2)
Shutoff Valves

p3_1_9_6.ct
Didactics material < Basics and working principles < Shutoff Valves < Graetz block 
Didactics material
Basics and working principles
Didactics material
The animation shows the actuation and spring return of a 4/2-way valve and the flow through the Graetz block during the advance and return strokes.      Similar rectifier circuits are also used in conjunction with line filters or brake valves.  
[130]  Graetz block
Graetz block 
Shutoff Valves

p3_1_9_7.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable non-return valve (1)
Didactics material
Basics and working principles
Didactics material
In the cases of delockable non-return valves, flow in the closed direction can be released by means of an additional pilot port (X). The illustration shows the valve in its normal position; flow from B to A is closed.      
[131]  Delockable non-return valve (1)
Delockable non-return valve (1)
Shutoff Valves

p3_1_9_8.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable non-return valve (2)
Didactics material
Basics and working principles
Didactics material
The released piston is pressurized via pilot port X. This lifts the sealing element from its seat and releases flow from B to A.      In order to release the valve reliably, the effective area of the pilot piston must always be greater than the effective area of the sealing element. Piloted non-return valves are also available with lockable non-return function.  
[132]  Delockable non-return valve (2)
Delockable non-return valve (2)
Shutoff Valves

p3_1_9_9.ct
Didactics material < Basics and working principles < Shutoff Valves < Delockable non-return valve (3)
Didactics material
Basics and working principles
Didactics material
The model circuit diagram shows how a load can be positioned by holding a cylinder using a suitable delockable non-return valve. The valve becomes active in the return stroke whereby the restriction on the piston side is released by actuation of the 3/2-way valve.      See also the animation 135 p3_1_9_11 on this topic.  
[133]  Delockable non-return valve (3)
Delockable non-return valve (3)
Shutoff Valves

p3_2.ct
Didactics material < Educational Films
Didactics material
Didactics material
Educational Films
Educational Films
Introduction
Fundamentals: Pressure fluids
Fundamentals: Pressure and Flow Rate
Fundamentals: Transmission of Force and Displacement
Fundamentals: Pressure Transmission
Fundamentals: Types of Flow
Basic Design of Hydraulic Systems
The Hydraulic Power Unit
Hydraulic Drives
Valves
Valves: Directional Control Valves
Valves: Non-Return Valves
Valves: Pressure Control Valves
Valves: Flow Control Valves
Representation of Hydraulic Systems in Circuit Diagrams

p3_2_1.ct
Didactics material < Educational films < Introduction 
Didactics material
Educational films
Didactics material
Introduction 
3:20
1 Introduction 

p3_2_10.ct
Didactics material < Educational films < Valves 
Didactics material
Educational films
Didactics material
Valves 
3:12
10 Valves 

p3_2_11.ct
Didactics material < Educational films < Valves: Directional Control Valves 
Didactics material
Educational films
Didactics material
Valves: Directional Control Valves 
10:39
11 Valves: Directional Control Valves 

p3_2_12.ct
Didactics material < Educational films < Valves: Non-Return Valves 
Didactics material
Educational films
Didactics material
Valves: Non-Return Valves 
1:59
12 Valves: Non-Return Valves 

p3_2_13.ct
Didactics material < Educational films < Valves: Pressure Control Valves 
Didactics material
Educational films
Didactics material
Valves: Pressure Control Valves 
4:24
13 Valves: Pressure Control Valves 

p3_2_14.ct
Didactics material < Educational films < Valves: Flow Control Valves 
Didactics material
Educational films
Didactics material
Valves: Flow Control Valves 
4:23
14 Valves: Flow Control Valves 

p3_2_15.ct
Didactics material < Educational films < Representation of Hydraulic Systems in Circuit Diagrams 
Didactics material
Educational films
Didactics material
Representation of Hydraulic Systems in Circuit Diagrams 
2:58
15 Representation of Hydraulic Systems in Circuit Diagrams 

p3_2_2.ct
Didactics material < Educational films < Fundamentals: Pressure fluids 
Didactics material
Educational films
Didactics material
Fundamentals: Pressure fluids 
2:02
2 Fundamentals: Pressure fluids 

p3_2_3.ct
Didactics material < Educational films < Fundamentals: Pressure and Flow Rate 
Didactics material
Educational films
Didactics material
Fundamentals: Pressure and Flow Rate 
2:41
3 Fundamentals: Pressure and Flow Rate 

p3_2_4.ct
Didactics material < Educational films < Fundamentals: Transmission of Force and Displacement 
Didactics material
Educational films
Didactics material
Fundamentals: Transmission of Force and Displacement 
1:35
4 Fundamentals: Transmission of Force and Displacement 

p3_2_5.ct
Didactics material < Educational films < Fundamentals: Pressure Transmission 
Didactics material
Educational films
Didactics material
Fundamentals: Pressure Transmission 
0:53
5 Fundamentals: Pressure Transmission 

p3_2_6.ct
Didactics material < Educational films < Fundamentals: Types of Flow 
Didactics material
Educational films
Didactics material
Fundamentals: Types of Flow 
2:10
6 Fundamentals: Types of Flow 

p3_2_7.ct
Didactics material < Educational films < Basic Design of Hydraulic Systems 
Didactics material
Educational films
Didactics material
Basic Design of Hydraulic Systems 
1:13
7 Basic Design of Hydraulic Systems 

p3_2_8.ct
Didactics material < Educational films < The Hydraulic Power Unit 
Didactics material
Educational films
Didactics material
The Hydraulic Power Unit 
3:26
8 The Hydraulic Power Unit 

p3_2_9.ct
Didactics material < Educational films < Hydraulic Drives 
Didactics material
Educational films
Didactics material
Hydraulic Drives 
6:58
9 Hydraulic Drives 

