Expansion Block/Orifice Tube: Description and Operation

A/C EVAPORATOR CORE ORIFICE







NOTE: A new A/C evaporator core orifice should be installed whenever a new A/C compressor is installed.

The A/C evaporator core orifice has the following characteristics:
- It is located in the aft condenser to evaporator tube.
- It has filter screens located on the inlet and outlet ends of the tube body.
- The inlet filter screen acts as a strainer for the liquid refrigerant flowing through the A/C evaporator core orifice.
- O-ring seals on the A/C evaporator core orifice prevent the high-pressure liquid refrigerant from bypassing the A/C evaporator core orifice.
- Adjustment or repair cannot be made to the A/C evaporator core orifice assembly. It must be installed as a unit. The evaporator core orifice can be accessed by separating a tube-O fitting in the condenser to evaporator line.

An A/C evaporator core orifice or O-ring seal is not considered a major component but a new A/C evaporator core orifice should be installed whenever a new A/C compressor is installed for lack of performance.