Hydropneumatic device transferring fuel between reservoirs - uses second stage valve having diaphragm, and pressure reducing valves controlled by fuel level

摘要

The compressed nitrogen is used to drive fuel from a reserve tank to the main tank. The gas passes from the bottle through first stage pressure reducing valve and then to the second stage valve. This second stage valve has a capsule which is connected to a diaphragm which is exposed to the pressure in the supply pipe to the main tank. As the level in the main tank falls the second stage valve admits gas to the container. This gas compresses the flexible inner tank and forces fuel towards the main tank.