CVPP is a pilot valve for differential-pressure available in low-pressure and high-pressure versions. The pilot valve is used to maintain a constant differential pressure between the CVPP pilot valve reference pressure connection and the ICS or PM pilot operated servo valves inlet pressure. CVPP incorporates a diaphragm so that the reference pressure and the refrigerant in the valve are physically separated. The pilot valve can therefore also be used as a pneumatic control valve either to control a ICS or PM pilot operated servo valve or as a separate pneumatic valve mounted in a CVH housing.