Airbus A340 Series, Brochure

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STL 472.502/90 Issue 6
A340 Fuel System
7.4
• In normal operation, each engine is independently
supplied by a continuously operating booster pump,
located in a dedicated collector box.
In the event of a pump failure, each engine is
automatically fed by a standby pump.
Collector boxes are maintained full by a jet pump
transfer action using booster pump pressure.
In cruise conditions, a single booster pump is able to
supply flow to all four engines.
• A crossfeed valve is associated with each engine. It
connects the engine and its associated pumps to the
X-FEED line. This allows any pump to supply any
engine.
All crossfeed valves open automatically in electrical
emergency configuration and during jettison operation.
• Supply of fuel to each engine may be shut off by an
engine LP valve driven by a double motor actuator. It
is controlled by either the ENG FIRE pushbutton or
the ENG master lever.
• Automatic control of transfer from center to inner
tanks is initiated, provided either center tank pump
pushbutton is selected on.
With fuel in the center tank and CTR TK pumps
running, both inner inlet valves are used
independently to cycle the inner tank contents
between underful and high level. (Underful is set at
approximately 2000 kg below high level).
When the center tank is empty, the pumps are
automatically controlled off, and both inner inlet
valves lose.
• Automatic transfer of fuel from the outer tanks is
performed by gravity. This occurs when center and
trim tanks have been emptied and when either inner
tank reaches 4000 kg.
Outer tank fuel transfer valves are used to cycle the
inner tanks contents between 4000 and 4500 kg.
These valves are closed when outer tanks are empty
for 5 minutes.
• Transfer to inner tanks can be manually selected
through the OUTR TK XFR pushbutton.
When selected ON, all inner tank fuel transfer, outer
inlet and inner inlet valves are controlled OPEN.
• Automatic control of transfer from ACT to center tank
occurs after takeoff slats restriction, provided the
center tank contains less than 23000 kg.
Engine feed