Expansion Block/Orifice Tube: Description and Operation

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

The evaporator core orifice has the following characteristics:
^ It is located in the evaporator core inlet 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 evaporator core orifice prevent the high-pressure liquid refrigerant from bypassing the evaporator core orifice.
^ Adjustment or service cannot be made to the evaporator core orifice assembly, a new evaporator core orifice assembly must be installed as a unit.