PRV-20 Differential check valve is situated on the 3/8’’SAE connector on the top of the oil receiver. It can release the pressure from oil receiver to suction pipes, so that it can keep the pressure to a fixed number. If there is enough oil in the oil receiver, then differential check valve will ensure the oil to flow from oil receiver to oil regulator.

Pressure differentia initialization: 20psi (1.38bar)