Gas Air Pilot Compressor Unloader Check Valve Combo 140 - 175 PSI 1/2" Female

This piloted discharge check valve is a combination of a pilot valve, a pressure discharge valve, and check valve in one complete piece to make a constant run air compressor with gas engine or electric motor. This valve will relieve the pressure the compressor is pumping out to the atmosphere through a silencer so the compressor can stay running without building pressure.

eBay