Patent ID: 8789794

Claim:
An apparatus comprising: a tube configured to carry an inert gas in a fuel tank; an opening in the tube; and a valve associated with the opening, the valve comprising: a substantially cylindrical portion connected to the tube and configured to rotate around the tube to open and close the opening based on a position of the cylindrical portion; and a float structure connected to the cylindrical portion, the float structure buoyant in the fuel, movement of the float structure rotating the cylindrical portion, and the valve configured to control an amount of the inert gas that exits the opening based on a level of fuel relative to the opening, such that when a fuel level is below a first level the valve is closed, when the fuel level is at a second level, relatively higher than the first level, the valve is partially open, and when the fuel level is at a third level, relatively higher than the second level, the valve is fully open.