Expansion Valve: Description and Operation

The expansion valve regulates the flow of liquid refrigerant into the core of the evaporator. As the condensed liquid refrigerant travels through the expansion valve, the refrigerant pressure decreases considerably. As the pressure drops, the refrigerant temperature drops. The refrigerant that is passing through the expansion valve changes from a high-pressure liquid with a medium-temperature into a low-pressure liquid with a low-temperature.