The HSF-M valve is a non-pressure compensated finely adjustable orifice for adjustment of flow in one direction and allowing limited free flow in the other for use as a uni-directional flow regulator actuator.

The main spool (sleeve) is held on the seat in the body by a spring. As the adjustment knob is turned counter-clockwise, the adjusting strew is backed out of the sleeve. The adjusting screw regulates flow thru the side of the body into the center of the main sleeve and out port 1 at the bottom of the body. Flow (pressure) in the opposite direction (port 1) forces the sleeve to open against the spring and allows limited flow (depending on the adjustment screw position) from port 1 to 2. Pressure curves indicate closed (worst) condition.

This valves is constructed of steel parts, and operating parts are hardened and ground as required. The cartridge is designed for easy service and field repair.