High Pressure Safety Valve HVAC - Description and Operation
High Pressure Safety Valve HVAC: Description and Operation
HIGH PRESSURE RELIEF VALVE
A high pressure relief valve is located on the compressor cylinder head, which is at the rear of the A/C compressor. 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.
The high pressure relief valve vents refrigerant from the A/C system when a discharge pressure of 3445 to 4135 kPa (500 to 600 psi) or above is
reached. The high pressure relief valve closes with a minimum discharge pressure of 2756 kPa (400 psi) is reached.
The high pressure relief valve vents only enough refrigerant to reduce the A/C system pressure, and then re-seats itself. The majority of the refrigerant is
conserved in the A/C system. If the high pressure relief valve vents refrigerant, it does not mean the valve is faulty.
The high pressure relief valve is factory-calibrated and cannot be adjusted or repaired, and must not be removed or otherwise disturbed. The valve is
only serviced as a part of the A/C compressor.
