The HS2W cartridge is used to allow (open) or block (close) flow, in a single line of a circuit, when actuated by a pilot valve.

The HS2W valve can be pilot operated by connecting port 1 and an electric, pneumatic, pr manual operated pilot valve. Port 4 must be connected to drain (unless a four-way pilot control valve is used). The main spool is available in a normally open or normally closed configuration. The spool is held in its normal position by a spring. Pressure piloted to port 1 shifts the spool against the spring to open or close flow between ports 2 and 3. Draining port 1 allows the spring to shift the spool to its original position.

Normally open or normally closed pilot operated valves are constructed of steel parts, operating parts are hardened and ground as required. Cartridge is designed for easy service or field repair.