E 150 1/2 Ton Van V6-4.2L VIN 2 (1997)
Expansion Valve: Description and Operation
THERMOSTATIC EXPANSION VALVE
Thermostatic Expansion Valve
An A/C evaporator expansion valve automatically regulates the flow of refrigerant into the A/C evaporator core in the auxiliary A/C-heater unit. It is also
the dividing point in the system between low- and high-pressure sides.
The temperature sensing bulb, clamped to the suction (outlet) tube on the A/C evaporator core, measures the temperature of the refrigerant in the suction
tube and transmits it to the A/C evaporator expansion valve. This temperature variation regulates the refrigerant flow to the A/C evaporator core. When
the bulb senses a high temperature, the A/C evaporator expansion valve opens and floods refrigerant through the A/C evaporator core. When the bulb
senses a low temperature, the A/C evaporator expansion valve starts closing to shut off the refrigerant to the A/C evaporator core.
