High Pressure Relief Valve

A high pressure relief valve is located on the compressor cylinder head at the rear of the A/C compressor. See Heating and Air Conditioning/Plumbing/COMPRESSOR, A/C - Description . This mechanical valve is designed to vent refrigerant from the A/C system to protect against damage to the A/C compressor and other A/C system components caused by condenser air flow restriction or an overcharge of refrigerant.