This is a model of a check valve with lumped volumes and a third port for pilot operation. The pilot ratio of the valve, kp, determines the effect of the pilot pressure on the pressure difference, i.e. how much pilot pressure "helps" the pressure on port a.

If the pressure difference is higher than pMin, the valve begins to open. When the pressure difference has reached pMax, the valve is completely opened. If the pressure is lower than pMin, the valve is closed and has only leakage flow.

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. 186.

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
A	Value: 0.001 Type: Area (m²) Description: Opening area when opened
Cd	Value: 0.62 Type: Real Description: Coefficient of discharge for the opening
kp	Value: 1 Type: Real Description: Pilot ratio; a positive value helps port_a
t1	Value: 0.001 Type: Time (s) Description: Time constant for first-order system
pMax	Value: 100000.0 Type: Pressure (Pa) Description: Pressure when valve is fully open
pMin	Value: 100 Type: Pressure (Pa) Description: Pressure when valve starts to open