Pressure Relief Valve

The pressure relief valve is installed on the A/C compressor or reservoir.

Fig 1: Identifying A/C Refrigerant System Pressure Relief Valve

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

At a pressure of approximately 38 bar positive pressure, valve opens and closes again once pressure has dissipated (approximately 30 bar).

Refrigerant does not escape completely.

Depending on the version, a transparent plastic disc may be installed which breaks off as soon as the valve is activated.