A320 Pump Pressures Wing & Center Tnk
 

Hi
As there is a preferential use of Center Tank over Wing Tank fuel, does anybody know what the pumps pressure at the wing and center are?

Thanks

There are sequence valves. The pumps are identical but the sequence valves fitted to the pumps from the wing ensure the center tank fuel is used first.

From Eaton's web site: Airframe Fuel Pumps
Type 8410 (A320 wing tank) Delivery Pressure . . . . . . . . . . . . . . 200kPa (29psig)

All Pumps deliver the same pressure.
The sequence valve is simply spoken a check valve with different spring tension.
The sequence valves in the wing reduces the output pressure to 25 PSI, thus giving priority to the center tank pumps, whenever they are operating.

Excellent, thank you. Now all I have to do is find somebody :O to tell me where in the system schematic are the sequence valves located. I am thinking you see, about how do 4 PSI reducing springs downstream of wing pumps fit into the gravity feeding arrangement. (that is a question)

Then the first prize from the next pilot's ATA28 wisdom measuring contest is surely mine! :E

Sequence valves are pressure relief valves attached to the secondary outlets on the wing tank pumps only. These valves prevent the pump outlet pressure rising above 25 psi. This pressure is lower than center tank pump output pressure and therefore permits center tank delivery to predominate.
The main engine fuel pump is powered by the accessory gearbox driven by the engine, and this is what delivers fuel to the engine even if the tank pumps have failed.

Secondary outlet ... where? http://www.eaton.com/ecm/idcplg?IdcS...Name=CT_194798

Have some pictures..

http://i97.photobucket.com/albums/l212/sids666/pump.jpg


http://i97.photobucket.com/albums/l2...s666/pump2.jpg


http://i97.photobucket.com/albums/l2...s666/pump3.jpg

Thank you.

readback: The pumps provide identical pressure but actually the pressure coming from the wing tank pump's canister is less, effect of a "sequence valve" PRV designed to open at 25 psi.