This General Pump Unloader Valve (ZH288) is made with highly durable brass and stainless steel. This unloader has 1/2" inlets, 1/2" bypass ports, and a 1/2" outlet. It is rated for a maximum flow rate of 21 GPM and a maximum pressure rating of 4060 PSI.

Pressure sensitive, high-pressure unloader valves are designed to trap pressure when the spray gun is closed and drop the bypass pressure to zero. Immediate pressure becomes available when the spray gun is opened. Unloaders may be designed to respond to either an increase in pressure or a change in flow by adjusting the knob or screw on top of the spring.