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

The HS2W valve can be pilot operated by connecting ports 1 and 4 to an electric, pneumatic, or manual operated pilot valve. The main spool is available in a normally open or normally closed configuration. With port 1 drained and pressure at port 4, the spool is held in its normal position. Connecting port 1 to pressure and port 4 to drain shifts the spool to open or close flow between ports 2 and 3. If equal pressures are applied to both ports 1 and 4 at the same time, the larger area on the port 4 end of the spool will tend to move the spool to its normal position.

Valves are constructed of steel parts, operating parts are hardened, and cartridge is designed to easy service or field repair.