*
Pressure switch
*
Drain plug
*
Extraction lever.
Training Information Point
To remove the motor-impeller, you turn it 35 degrees CCW to close the inlet valve. Then you remove the drain plug to remove residual fuel. You use the extraction lever to move the motor-impeller out of the housing.
To install the motor-impeller, you must align pins in the housing to slots on the motor-impeller.
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ENGINE FUEL FEED -BOOST PUMP
You can remove the discharge, motive flow, and vapor vent valves through the housing from outside the tank.
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777 AIRCRAFT MAINTENANCE MANUAL
ENGINE FUEL FEED -BOOST PUMP
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D633W101-BEJ Sep 05/2002
ENGINE FUEL FEED -WATER SCAVENGE JET PUMP
General
The water scavenge jet pumps take fluid from the low points in the tanks and send it to the pump inlets. This prevents water from collecting in the bottom of the tanks.
Location
The water scavenge jet pumps are on the rear spar. There is one jet pump in each side of the center tank and one in each main tank.
Functional Description
The jet pumps operate automatically when the fuel pumps are on. They use fuel from the fuel pumps as motive fuel. The flow of the motive fuel through the jet pump causes suction that takes fluid from the low points in the tanks.
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ENGINE FUEL FEED -WATER SCAVENGE JET PUMP
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D633W101-BEJ Sep 05/2002
ENGINE FUEL FEED -MOTOR-ACTUATED VALVES
General
The fuel system has 11 motor-actuated valves. These seven valves have a valve body, an adapter/shaft and an actuator:
*
Engine fuel spar valves (2)
*
Fuel crossfeed valves (2)
*
Fuel jettison isolation valves (2)
*
Defuel valve.
These four valves have the same actuator, a different valve body, but no adapter/shaft:
*
APU fuel shutoff valve
*
APU fuel isolation valve
*
Fuel jettison nozzle valves (2).
Valve Body
The valve body connects two fuel lines. It has these parts:
*
Butterfly valve (not shown)
*
Operating shaft
*
Thermal relief valve.
There are no hard stops for the valve body. You look at alignment marks to find out if the valve is closed.
Adapter
The adapter/shaft mounts through the rear spar. It has these parts:
*
Mount plate
*
Index plate
*
Adapter shaft.
The adapter shaft connects the adapter to the operating shaft on the valve body.
The index plate attaches to the mount plate with three screws. You loosen these screws to rotate the index plate when you align the valve. You must get access to the valve body to check the valve position when you align it.
Actuator
The actuator is a 28v dc motor. It has a manual override lever that permits you to operate the actuator without electrical power. The lever aligns with marks on the adapter. This shows you the valve position.
You can remove the actuator without defueling the airplane.
Training Information Point
The valves use interchangeable actuators.
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777 AIRCRAFT MAINTENANCE MANUAL
ENGINE FUEL FEED -MOTOR-ACTUATED VALVES
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ENGINE FUEL FEED -SPAR VALVE BATTERY
Purpose
The engine fuel spar valve battery makes sure that the fuel system always has power to close these shutoff valves:
*
Engine fuel spar valves
*
APU fuel shutoff valve.
Components
The engine fuel spar valve battery has these components:
*
Aluminum case
*
Battery pack
*
Printed circuit board assembly
*
Electrical connector.
Battery Assembly
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