JET PUMP OPERATION
When the related fuel pump is on, fuel goes into the jet pump through the inlet X. The fuel flows through the NRV and the jet nozzle. The jet nozzle decreases the pressure and increases the velocity of the fuel that goes through. This causes a suction force at the inlet Y that is connected to the lowest part of the tank.
The fuel at the inlet Y + Water caught in the tank mixed together and moved through the jet pump, mixed again with the fuel from the inlet X and distributed through the outlet Z.
JET PUMP FUNCTIONS:
1. mixes water caught in the tank with fuel and through it in front of the pump inlet.
2. In A320 'Old configuration' as Fuel spilled through the vent pipes into the surge tank, Jet pumps are used to scavenge that fuel and return back to the related outer cell tank.
3. In A321, A320 NEO and A320 CEO new configuration, are installed in the center tank and transfer the fuel from the center tank to the wing tanks (A320 inner cell)
To take advantage of this simplification, the transfer jet-pumps were introduced in the center tank of A319ceo and A320ceo aircraft delivered from 2014. and are standard on all A319neo, A320neo, and A321neo aircraft.
The fuel will still go to the wing tank by jet pumps but to inner cell only, outer cell will not take fuel unless during refueling on ground