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WOLFRAM SYSTEM MODELER

PressureReliefValve

Pressure valve, controlled by the pressure difference between the ports

Diagram

Wolfram Language

In[1]:=

SystemModel["Hydraulic.Valves.PressureControl.PressureReliefValve"]

Out[1]:=

Information

This is a model of a pressure relief valve with lumped volumes. If the pressure difference between the upstream and downstream port is higher than pMin, the valve starts to open. When the pressure difference reaches pMax, the valve is fully open. The spool model has first-order dynamics with time constant t1. This valve could be used for controlling the upstream pressure in a system (the part connected to port a).

A spool type pressure relief valve

Implementation

This valve basically consists of an orifice controlled by a spool.

Reference

Industrial Hydraulics Manual, 5th ed., Maumee, OH: Eaton Hydraulics Training Services, 2008 p. 277.

Parameters (8)

medium	Value: Oil() Type: Medium Description: Medium in the component
V	Value: 0.0001 Type: Volume (m³) Description: Volume of control valve
Gleak	Value: 9.999999999999999e-21 Type: PressureDependentLeakage (m³/(s⋅Pa)) Description: Leakage between ports
pMax	Value: 21000000.0 Type: Pressure (Pa) Description: Pressure when valve is fully open
pMin	Value: 20000000.0 Type: Pressure (Pa) Description: Pressure when valve starts to open
t1	Value: 0.01 Type: Time (s) Description: Time constant for first-order system
AMax	Value: 0.001 Type: Area (m²) Description: Maximum opening area
Cd	Value: 0.62 Type: Real Description: Coefficient of discharge for the opening

Connectors (2)

	port_b	Type: Port_b Description: Port for hydraulic fluid (unfilled icon)
	port_a	Type: Port_a Description: Port for hydraulic fluid (filled icon)

port_b

Type: Port_b

Description: Port for hydraulic fluid (unfilled icon)

port_a

Type: Port_a

Description: Port for hydraulic fluid (filled icon)

Components (4)

	medium	Type: Medium Description: Medium in the component
	pressureReliefValve	Type: PressureReliefValve Description: Static pressure relief valve
	volume_a	Type: Volume Description: Fixed volume with fluid storage
	volume_b	Type: Volume Description: Fixed volume with fluid storage

Used in Examples (14)

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	MeterOut Hydraulic.Examples.FlowControl Example circuit with meter-out flow control
	BleedOff Hydraulic.Examples.FlowControl Example circuit with bleed-off flow control
	SubCircuitWithReducedPressure Hydraulic.Examples.MultipleActuators Example circuit with a sub-circuit operating at a reduced pressure
	SequenceCircuit1 Hydraulic.Examples.MultipleActuators Example circuit with two cylinders working in a sequence
	SequenceCircuit2 Hydraulic.Examples.MultipleActuators Example circuit with two cylinders working in a sequence
	HydrostaticTransmission Hydraulic.Examples.Rotation Example circuit of a pump driving a motor
	OpenCenterHydraulicSystem Hydraulic.Examples.Rotation Example circuit with a pump that unloads to a reservoir when inactive
	BrakeCircuit Hydraulic.Examples.Rotation Example circuit with a brake valve
	Servo1 Hydraulic.Examples.Translation Example circuit of a cylinder moving a load
	Servo2 Hydraulic.Examples.Translation Example circuit of a cylinder moving a load with the help of a simple controller
	Servo3 Hydraulic.Examples.Translation Example circuit of a cylinder moving a load
	LoadHoldingCircuit Hydraulic.Examples.Translation Example circuit of a cylinder lifting and holding a mass
	Filters Hydraulic.Examples.Filter Example of a hydraulic system using filters