Tank gas flow restrictor - has two coaxial valves functioning in opposite directions to relieve pressure

摘要

The system is particularly for motor vehicle petrol tanks, restricting the gas flow in and out, resulting from pressure differences. It has two coaxial pressure relief valve working in opposite directions. The valves can be combined with a component of the tank, such as the filler cap or the vent, and they can have an external sealing ring bearing against the cap. The valve allowing flow out of the tank can be arranged to open at 0.30 Kg, per sq. cm., and the other at 1/30 kg, per sq.cm. The assembly can have upper and lower components with passages, through them, with a component incorporating a central chamber inbetween, to which both passages are connected. The valve itself has one section regulating gas flow into the chamber, and the other one out of it.