The screw-in check valves with hydraulic release type CRH and RHC are used in hydraulic circuits together with design related, leaking directional valves, as a hydraulically actuated drain, or idle circulation valves. The valves type RHC with or without pre-release (for high pressure and high consumer flows) are designed as screw-in valves. Type CRH valves are designed as a valve cartridge. Many different versions are available to cover all requirements. Both types can be screwed in mounting holes which can be easily machined with a standard drill (point angle 118°).