Legacy Outback Ltd Sedan F4-2.5L SOHC (2000)
Expansion Valve: Description and Operation
Function
Expansion Valve
If the heat load of the air conditioner system increases, the refrigerant temperature at the evaporator outlet rises and therefore increases the pressure P1 at
around the temperature sensing area. As this pressure P1 becomes higher than the resultant force Of evaporator outlet (low pressure side) pressure P2
and the spring force F (P1 > P2 + F), the diaphragm is pressed down, opening the valve ball connected to the diaphragm to increase the flow of the
refrigerant.
If the heat load decreases, the action contrary to the one mentioned above takes place, closing the valve to decrease the flow of the refrigerant.