Unloading Valve Subplate mounted unloading valves series R4U are used to unload a circuit at low pressure. The mechanically adjustable pressure signal to unload the main stage has to be applied to port X. The pressure differential between opening and closing is nominal 15 or 28 % of the setting pressure:
28 % for pressure stages 105 and 210 bar
15 % for pressure stage 350 bar