Parker Constant Pressure Expansion Valve Adjustable 0.88 to 4.24 Tons 90 psig

Parker Constant Pressure Expansion Valve

The Parker Constant Pressure Expansion Valve is an externally adjustable component designed for HVAC and refrigeration systems. It maintains constant evaporator pressure across all load conditions and functions as a low load protection device in hot gas bypass applications. The valve operates within a nominal capacity range of .88 to 4.24 tons. Its adjustable range spans 5 in Hg vacuum to 90 psig.

SAE Flare and NPT Connections

This valve features a 1/4 in SAE flare angle inlet and a 1/4 in NPT outlet connection for integration into existing piping. The external adjustment mechanism allows technicians to set the desired pressure without removing the valve from the line. It frees up system design flexibility by regulating pressure independently of load fluctuations. No capillary tube or reducing flare nut is included with this model.

Pressure Regulation and System Stability

In normal operation the valve modulates refrigerant flow to hold a steady evaporator pressure, reducing compressor cycling and preventing low-pressure cutouts. The adjustable range up to 90 psig supports a wide variety of low-temperature and medium-temperature applications. Stable pressure control contributes to consistent system performance and reduced mechanical stress on downstream components.