The high pressure relief valve vents refrigerant from the A/C system when a discharge pressure of 3430 to 3930 kPa (497 to 570 psi) or above is reached. The high pressure relief valve closes with a minimum discharge pressure of 2990 kPa (4370 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.