Eaton’s high- and low-level float control valves are used in combination with pilot, shutoff and refuel/defuel valves to fuel and defuel aircraft, drop and auxiliary tanks on commercial and military aircraft. The refuel shutoff valve provides a pilot function. When the pilot valve is open, fuel flows from its inlet to the tank and the refuel valve remains open. When the pilot valve is closed, fuel flow stops and fuel pressure closes the refuel valve. The pilot valve can be opened and closed mechanically by float action and/or electrically by solenoid.
The low-level pilot valve is used in combination with a refuel/defuel valve. During suction defueling, the fuel level drops to the low-level pilot valve’s shutoff level, opening the low-level pilot valve and allowing tank pressure to the back side of the refuel/defuel valve’s poppet to close the refuel/defuel valve and prevent air from being drawn into the manifold.