Pressure Relief Valve
Non-approved tools or materials such as leak sealing additives can cause damage or malfunctions in the system.
Only use tools and materials approved by the manufacturer.
The warranty is voided if non-approved tools or materials are used.
- All components of the refrigerant circuit submitted for quality observation are always to be sealed (use original sealing caps of original part).
- Replace damaged or leaking components of refrigerant circuit. Refer to COMPONENTS, REPLACING .
- To date, the original parts (compressor, reservoir, receiver/dryer, evaporator and condenser) have been filled with nitrogen gas. This charge is being gradually discontinued. There is little or no pressure equalization when removing the sealing plugs from the original part.
The pressure relief valve is installed on the A/C compressor or receiver/dryer.
At a pressure of approximately 38 bar (551 psi) positive pressure, valve opens and closes again once pressure has dissipated (approximately 30 bar (435 psi)).
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.
Depending on the version, a transparent plastic washer -B- may be installed on the pressure relief valve -A-, which breaks off as soon as the valve is activated.
Depending on the pressure relief valve version -A-, an additional cover -C- can be slid onto the pressure relief valve -A-. If the pressure in the refrigerant circuit does rise above the pressure relief valve -A- opening pressure and the pressure relief valve opens, the refrigerant does not escape in one direction, but rather it is distributed through the openings -D- under the cover -C-.
If it is necessary to replace a pressure relief valve -A- pay attention to the tightening specification when installing (depending on the manufacturer of the A/C compressor and the version). For "Denso", "Sanden" and "Valeo" A/C compressors, an O-ring is installed (tightening specification currently 10 Nm on "Denso" and "Zexel- / Valeo" and 15 Nm on a "Sanden" A/C compressor). On a "Delphi" A/C compressor, a seal is installed, for example (tightening specification currently 15 Nm).
Replace the seals (seal or O-ring). Refer to the Parts Information.
If the seals (seal or O-ring) that are installed on the pressure relief valve are not available as a replacement part, the removed seals may be used as an exception (check for damage before installing). If the removed seal is damaged or deformed if necessary replace with a commercially available component. Refer to the Parts Information.
After charging the refrigerant circuit check the installed pressure relief valve for leaks for example using an electronic leak detector.