The porous plastic expansion (orifice) tube, with its porous plastic inlet and outlet filters and brass orifice tube, is located between the condenser outlet and evaporator inlet. It provides a restriction to the high-pressure liquid refrigerant in the liquid line, metering the flow of refrigerant to the evaporator as a low-pressure liquid. The expansion (orifice) tube is protected from contamination by filters on both the inlet and outlet sides. When system diagnostics indicate a restricted expansion (orifice) tube, it may not be necessary to replace the expansion (orifice) tube. Metal chips, flakes, or slivers found on the inlet filter may be removed with compressed air ONLY and the expansion (orifice) tube may be reused if: