F 250 4WD Super Duty V10-6.8L VIN Z CNG (2003)
Expansion Valve: Description and Operation
Auxiliary Climate Control
An A/C evaporator expansion valve automatically regulates the flow of refrigerant into the auxiliary A/C evaporator core. It is also the dividing point in
the system between low- and high-pressure sides.
The temperature sensing bulb measures the temperature of the refrigerant in the suction line and transmits it to the A/C evaporator expansion valve. This
temperature variation regulates the refrigerant flow to the auxiliary A/C evaporator core.
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When the bulb senses a high temperature, the A/C evaporator expansion valve opens and floods refrigerant through the auxiliary A/C evaporator
core.
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When the bulb senses a low temperature, the A/C evaporator expansion valve starts closing to shut off the refrigerant to the auxiliary A/C
evaporator core.
