Expansion Block/Orifice Tube: Description and Operation

The A/C evaporator core orifice is a restriction between the high and low-pressure liquid refrigerant. This A/C evaporator core orifice meters the flow of liquid refrigerant into the A/C evaporator core.

The A/C evaporator core orifice is color-coded Green and, has an 1.32mm (0.052 in) orifice. It is located in the liquid line near the A/C condenser core. Filter screens are positioned on the tube inlet and outlet ports. O-rings on the tube body prevent the liquid refrigerant from bypassing the A/C evaporator core orifice. The A/C evaporator core orifice can be removed from the liquid line and serviced.