Best Price on Air Brake Unloader Valve - HKW DOUBLE-DIRECTION HYDRAULIC LOCK – Hanshang Hydraulic

Flow is allowed to pass in one direction(V1 to C1 or V2 to C2),then the valve remains closed(checked) in both reverse directions(C1 to V1 or C2 to V2) in order to hold and lock in position the cylinder or other actuators;reverse flow is possible only when sufficient pilot pressure is applied at V2 or V1,which act as cross connected pilot ports,and the pilot piston lifts the poppet from its seat overcoming cylinder port pressure.