The HSC cartridge type check valve allows flow in one direction but prevents flow in the other. Several "cracking pressure" springs are available to regulate the pressure at which flow starts. The valve can be used to separate portions of a circuit, or with a sequence valve to provide a counterbalance function.

Pressure at port 1 forces the poppet off the seat and compresses the spring to allow flow to port 2. Reverse flow (from port 2) or a higher differential pressure, works on top of the poppet and forces it against the seat to stop flow.

Several springs are offered for regulating the cracking pressure. The valve is constructed of steel parts, operating parts are hardened and ground as required. The cartridge is designed for easy service or field repair.