Expansion Block/Orifice Tube: Description and Operation

A/C Evaporator Core Orifice:

NOTE: Install a new evaporator core orifice 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 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 repair cannot be made to the evaporator core orifice assembly, it must be replaced as a unit