Torque Pilot Check Valve

Pilot-controlled inspection Valves, like direct operated valves, allow free flow in one direction but block flow in the opposite direction; however, pilot operated valves allow reverse flow when a pilot pressure indication is provided to the valve's pilot port.
A primary poppet and a decompression poppet, which is significantly smaller than the check valves' pilot piston, make up the valve's two poppets. When the device is in operation, the release poppet opens first, releasing pressure holding the main poppet closed. The pilot piston forces the main poppet into the open position to enable complete reverse flow when this pressure is acceptable.