The Cla-Val Model 90-05 Pressure Reducing Valve is a full port valve that automatically reduces a higher inlet pressure to a steady lower downstream pressure, regardless of changing flow rate and/or varying inlet pressure. This valve is an accurate, pilot-operated regulator capable of holding downstream pressure to a pre-determined limit. When downstream pressure exceeds the pressure setting of the control pilot, the main valve and pilot valve close drip-tight. A CDC/CSC check valve is included to allow return flow when outlet pressure is greater than the inlet pressure. The 690-05 is the reduced port version of the 90-05.