A/C Orifice Tube - Operation

OPERATION

The variable A/C orifice valve (VOV) is used to meter the flow of liquid refrigerant into the A/C evaporator. The high-pressure liquid refrigerant from the A/C condenser expands into a low-pressure liquid as it passes through the metering orifices and diffuser screen of the A/C orifice valve. There are two parallel flow paths integral to the A/C orifice valve, a fixed port and a variable port. As the temperature of the refrigerant increases, the bimetal coil moves the variable port to the closed position. High temperature results in more restriction, and lower temperature results in less restriction. This design improves A/C cooling at high loads and/or city traffic.

The variable A/C orifice valve cannot be repaired or adjusted and the A/C liquid line must be replaced if inoperative or damaged.