RQR3-P, RQR5-P, RQR7-P, RQA5-P and RQA7-P are automatic unloading valves for subplate mounting. These valves are specific for circuits with accumulator, to optimize the energy consumption of the pump when the accumulator has reached the expected pressure level. They act deviating all the pump flow to the tank when the pressure value adjusted by the screw is reached, until the pressure in the working line B drops to a percentage (63% or 75%, depending by the version) of the set pressure. Then, the pump flow to the circuit is restored by means of the check valve until set pressure is reached again. RQA5-P and RQA7-P are already equipped with the check valve. Instead, RQR3-P, RQR5-P and RQR7-P have a X port for a pilot signal from a remote check valve. Three pressure control ranges up to 280 bar are available, adjustable by a hexagonal head screw. Upon request they can be equipped with a SICBLOC adjustment knob. The absence of the accumulator, an incorrect pre-charge value or the incorrect calibration of the pressure value on the valve cause valve to switch continuously creating sudden pressure surges in the circuit.