Expansion Valve: Description and Operation

GF83.40-P-2190GZ Expansion Valve, Component Description
- with CODE (582) Rear air conditioner

Component Identification:

Location
The expansion valve is located in the engine compartment at the left rear.

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

Function
When the refrigerant compressor (A9) is switched on, the pressure in the evaporator decreases causing a diaphragm in the expansion valve to arch. The diaphragm motion is transferred to a linkage. The linkage presses the valve ball out of its seat opening the valve. The opened valve enables the refrigerant to be sprayed into the evaporator.

Since the motion of the diaphragm depends on the suction pressure, as well as the temperature at the evaporator outlet, only the quantity of refrigerant which can evaporate optimally is injected.