Expansion Block/Orifice Tube: Description and Operation

EVAPORATOR CORE ORIFICE

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.