The constant pressure expansion valve responds to outlet pressure. It meters liquid refrigerant to the evaporator, maintaining a constant evaporator pressure.
Refrigerant flows at a rate that exactly matches compressor capacity.
The constant pressure expansion valve is ideal control for many refrigeration applications. The valve also can be used as a low load protection device in hot gas by-pass systems. Advantages - Simple, inexpensive, reliable . It moves the diaphragm down, opening the valve. Force 2 - the closing spring beneath the diaphragm.