Expansion Block/Orifice Tube: Description and Operation

EVAPORATOR CORE ORIFICE TUBE

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

The A/C evaporator core orifice has the following characteristics:
- It is color-coded red.
- It is located in the condenser to evaporator line.
- 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 tube.
- O-ring seals on the evaporator core orifice tube prevent the high-pressure liquid refrigerant from bypassing the evaporator core orifice tube.
- it can be accessed through a fitting located near the middle of the condenser to evaporator line.
- Adjustment or service cannot be carried out to the evaporator core orifice tube. A new evaporator core orifice must be installed.