Audi Workshop Service and Repair Manuals > A4 Mk3 > Heating, ventilation, air conditioning system | Air conditioner with refrigerant R134a | Air conditioner | General information on refrigerant circuit | Layout of components of refrigerant circuit and their influence on high-pressure and low-pressure sides

High-pressure safety valve

The high-pressure safety valve is fitted to the air conditioner compressor or the receiver.

The valve opens at a pressure of approx. 38 bar and closes again when the pressure has dropped (approx. 30 bar).

Not all the refrigerant escapes.

Certain versions feature a transparent plastic disc which breaks off as soon as the valve responds.