Fuel tank with venting valve

摘要

A fuel tank 1 has a venting valve 2 actuated by a float 10 which can admit fuel to vary the float's buoyancy. The float may have a foam- or sponge-like body, or may have a hollow body with at least one orifice 11. The float may have sieve-like or fuel-permeable walls, and may comprise an additional float element 9. The valve closes under gravity if the fuel tank is inverted (see fig 4). The valve protects the tank from overfilling by closing automatically when the fuel reaches a certain level. Float 10 then sinks as it fills with fuel, thus reopening the valve and protecting the tank from excessive pressure build up.