Check Valves
WARNING: This page is about a different car, the 2024 Audi S6 and 2024 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
The check valves separate the refrigerant circuit in different areas.
NOTE:
For example, the illustrated check valve -3- is installed on an Audi Q7 e-tron.
The check valves in the refrigerant circuit have a specified residual pressure (approximately 0.1 bar (1.45 psi) or 100 mbar (1.45 psi)) in the flow direction. So that the refrigerant circuit can be completely evacuated (residual pressure less than 5 mbar (0.07 psi)), all electrically activated valves must be opened.
Depending on the version, the flow direction may be marked with a sticker.