The examples show ventable relief valves used to either fully unload the pressure in a system, or reduce the maximum pressure setting.
- Ventable relief valves: RV*A, RBAE, RV*T
- Directional control valves: DN*C
Benefits of this circuit arrangement:
- Fig.1 shows a ventable pressure relief valve RV*A. Port 3 sees a pilot relief valve RBAE with a setting (1500 psi) below the setting (3000 psi) of the RV*A. The system pressure falls to the RBAE setting when DTDA opens. The spool-type valve RV*A can be replaced with a poppet type RV*S.
- Fig. 2 shows a ventable anti-shock relief valve RV*T. A 3/4-way valve DNDC-XYN in the vent line 3 of the RV*T offers the following options:
a) Sets the RV*T to 3000 psi in its de-energized state
b) Sets the RV*T to 1500 psi by enerizing solenoid A
c) Vents RV*T to tank with 0 pressure setting by energizing solenoid B
