fuel pump oil pressure dependent

The maximum pump oil pressure of the fuel pump depends on the standard of the pressure limiter. If the fuel pump pressure exceeds the predetermined pressure limit, the pressure limiter will open the bypass to allow the fuel to flow back to the fuel pump inlet.

Electric centrifugal booster pump

On some aircraft, the electric centrifugal booster pump is used as an auxiliary fuel pump in the fuel system. The motor is usually mounted on the spar corresponding to the lower part of the fuel tank, while the pump body is submerged in the fuel at the bottom of the tank. Take sealing measures between the pump impeller and the motor to prevent fuel or oil vapor from leaking into the motor. When the fuel enters the pump body, the high-speed rotating impeller projects the fuel outward in the radial direction, generating centrifugal force, increasing the fuel pressure, and delivering the fuel to the system. The rotary agitation of the pump also has the effect of separating air and oil vapor from the fuel, so that the fuel supplied to the engine does not contain oil vapor.