A/C Orifice Tube: Operation
WARNING: This page is about a different car, the 2004 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
The fixed A/C orifice tube is used to meter the flow of liquid refrigerant into the evaporator coil. The high-pressure liquid refrigerant from the condenser expands into a low-pressure liquid as it passes through the metering orifice and diffuser screen of the A/C orifice tube.
The A/C orifice tube is not serviceable. The A/C orifice tube cannot be repaired and, if faulty or plugged, it must be replaced as part of the liquid line.