GF83.65-D-4120H Roof Air Conditioning Expansion Valve, Component Description

GF83.65-D-4120H Roof Air Conditioning Expansion Valve, Component Description

- with CODE (H08) High-performance air conditioning







45 Roof air conditioning expansion valve
47 Roof air conditioning evaporator
A32/3 Rear heavy duty automatic air conditioning recirculation unit

Location
The roof air conditioning expansion valve is located in the feed and return line of the rear heavy duty automatic air conditioning recirculation unit on the vehicle roof.

Task
The roof air conditioning expansion valve regulates the flow of refrigerant to the roof air conditioning evaporator depending on the low pressure (gaseous) and the temperature at the roof air conditioning evaporator outlet.







Design and function
56 Diaphragm
57 Aluminum housing
58 Control valve
59 Ball
60 Spring

When the 2nd refrigerant compressor (A9/7) is switched on, there is a decrease in suction pressure in the line that leads from the roof air conditioning evaporator to the 2nd refrigerant compressor. This causes the diaphragm to bend downwards. The control valve follows the movement of the diaphragm and presses the ball out of its seating against the spring. This in turn enables more refrigerant to flow over the roof air conditioning expansion valve into the roof air conditioning evaporator. More refrigerant evaporates in the evaporator and the suction pressure is increased in the line leading from the roof air conditioning evaporator to the 2nd refrigerant compressor.This causes the diaphragm to bend upwards. The control valve follows the movement of the diaphragm and the spring force of the spring presses the ball onto its seating. This in turn enables less refrigerant to flow over the roof air conditioning expansion valve into the roof air conditioning evaporator. Less refrigerant evaporates in the evaporator and the suction pressure is decreased again in the line leading from the roof air conditioning evaporator to the 2nd refrigerant compressor.
The flow of coolant into the roof air conditioning evaporator is regulated by the roof air conditioning expansion valve. The movement of the diaphragm depends on both the suction pressure as well as the temperature at the roof air conditioning evaporator outlet. Only as much refrigerant is admitted as can be efficiently evaporated by the roof air conditioning evaporator.