GLOSSARY

EXPANSION VALVE: A DEVISE USED CONTROL AND METER REFRIGERANT FLOW

TO A HEAT EXCHANGE DEVICE. THIS IS DONE BY AN EXTERNALLY CONTROLLED

ASSEMBLY WHICH REDUCES THE  PRESSURE OF THE REFRIGERANT TO LOWER

THE TEMPERATURE WHILE INJECTING A SATURATED VAPOR INTO THE HEAT

EXCHANGE DEVICE. THE CONTROL DEVICE MAY BE A BULB SENSING DEVICE

OR AN ELECTRONIC EVAPORATOR TEMPERATURE CONTROL WHICH OPENS

AND CLOSES THE EXPANSION VALVE DIAPHRAGM  IN RELATION TO THE

EVAPORATOR OR HEAT EXCHANGER TEMPERATURE.