Dual-impeller, electrically driven.
Single-impeller, electrically driven
Cable-operated gate valve.
Motor-operated butterfly valve.
Fuel pressure-operated gate valve
Solenoid-operated butterfly valve
Air refueling pumps must be operated.
Main tank pumps must be operated.
Alternate pumps must be operated
Override pumps must be operated
Gravity feed valve must be opened.
Override wing valves must be opened.
Tank to manifold valves must be opened
Air refueling to engine manifold valves must be opened
Provide an ample supply of fuel in case of a single pump failure.
Prevent fuel boiling and evaporation in the wing tanks at high altitudes.
Provide fuel to the engines during negative Gs or inverted flight conditions.
Prevent the reverse flow of fuel from a pump with a greater pressure output.
A rotary-vane centrifugal pump is used.
A dual-impeller centrifugal pump is used.
An in-line ejector centrifugal pump is used.
A top-mounted pump centrifugal pump is used.
A two-way check valve.
A one-way check valve.
An impeller screen.
An inlet screen.
Requires special tools to install.
It isn’t possible to install the wrong pump.
Shortens the time required for pump changes.
Does not require either physically entering or completely defueling the tank.
Direction of fuel flow.
Direction of restricted flow.
Location of the drilled hole in the valve.
Location of the manufacturer’s data block.
Gravity flow or pump pressure.
An electrical impulse to the flapper mechanism.
Pressure relief valves
Thermal relief valves.
One-way check valves.
Spring-loaded check valves.
Operate the component while looking for leaks.
Pressurize the manifold with fuel and look for leaks
Stand-test with fuel for 30 minutes and look for leaks
Pressurize the manifold with air and listen for leaks.
Power to the boost pump.
A pressure switch reading
Continuity of the pressure switch.
A direct pressure reading of the pump.
Forward body tank.
Center wing tank.
A stuck open check valve.
A malfunctioning boost pump.
An inoperative pressure transmitter
Foreign object damage stuck in a shutoff valve.
Pressurize the tanks only.
Augment fuel transfer only.
Pressurize and scavenge the tanks.
Augment fuel transfer and scavenge the tanks
Ejector-type; located in the F–2 tank
Turbine-type; located in the F–2 tank.
Ejector-type; located in the F–1 tank.
Turbine-type; located in the F–1 tank.
The external centerline tank will transfer first.
The left wing external tank will transfer first.
The right wing external tank will transfer first.
Both wing external tanks will transfer first.
Inoperative wing float valve.
External transfer shutoff valve is bad.
External vent and pressurization valve is bad.
Centerline refuel/transfer valve is inoperative.
Transfer pumps are inoperative.
Refuel/transfer valves are inoperative.
Vent and pressurization valve is inoperative.
Centerline tank manual shutoff valve is inoperative.
Hydromechanically and controlled by fuel pressure.
Hydromechanically and controlled by a solenoid.
And controlled hydromechanically.
And controlled by a solenoid.