Torque Relief Valves

Does anyone know anything about this topic?
It certainly can't be a small amount.

It's been taken care of.
After I finished everything, it simply wouldn't start. I wasn't initially surprised, as it's known to be sensitive to air. However, fiddling with it seems to have damaged the fuel control unit. In the early years, Bosch used solder that wasn't sufficiently temperature-resistant. Perhaps loosening the old fittings caused enough stress to be the final straw.
Great, I'll have checked all the theoretically possible faults of AFB, AKN & Co. soon. I'll probably do the NW (likely referring to a specific component or system) next year, and I'll also check the oil pump chain then...