Expansion Block/Orifice Tube: Description and Operation

Evaporator Core Orifice Tube

NOTE: Install a new evaporator core orifice whenever a new A/C compressor is installed

The evaporator core orifice has the following characteristics:
- color-coded orange
- an orifice diameter of 1.46 mm (0.0575 inch)
- located in the condenser to evaporator line
- changes the high-pressure liquid refrigerant into a low-pressure liquid
- filter screens located on the inlet and outlet ends of the orifice 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 repair cannot be made to the evaporator core orifice. A new evaporator core orifice must be installed.