The check valves type HR with hydraulic release, are designed as manifold mounting valves and are available in six sizes. These valves are used in hydraulic circuits with design related, leaking directional valves, as hydraulically actuated drain, or idle circulation valves. The check valve type HRP can be ordered also with a pre-release to suppress decompression surges for circuits with high pressure and high consumer flows. This valve is tolerant to residual pressure in the return duct (port B) as the rear side of the actuation piston is depressurized via a leakage port. Another option allows opening of the check valve via the load pressure on the consumer side, controlled by a directly mounted solenoid valve.