A back pressure valve is usually installed on closed-type air suspension supports in case of a broken pneumatic line (pipe) or any other leakage so that all air does not come out of the air suspension cylinder. Otherwise, all the air will come out, and the rubber sleeve will bend, and it will simply tear it off with the details of the air suspension itself.
But in this case, there will be 5-6 atmospheres of air in the air suspension, and it will work in the normal mode. The pillow will still get on the bump stops, but the sleeve will be filled with air, so it will not tear. But if leakwill happen in the cylinder, the valve will not save. Although, in practise happened that the valves on the front cylinders of the Tuareg fell off, the air suspension was chewed, but whole, without a break.