Expansion Valve, Basic Function - GF83.40-P-2018A

MODEL ALL (CAR) 

Location 

The expansion valve is located at the rear in the engine compartment on the line passage to the vehicle interior.

General 

The expansion valve sprays liquid refrigerant into the evaporator. The injection quantity depends on the pressure and the temperature of the refrigerant supplied.

Design 

Function 

When the air conditioning is switched on, the pressure in the evaporator decreases, causing the diaphragm in the expansion valve to arch. The diaphragm motion is transferred to a linkage. The plunger forces a valve ball out of its seat, which in turn opens the valve.

The opened valve enables the refrigerant to be sprayed into the evaporator. The movement of the diaphragm depends on both the suction pressure and the temperature at the evaporator outlet. This means that only the amount of refrigerant that can evaporate optimally is injected.