What kind of fuel boost pumps are normally installed inside the fuel tanks?

• A. Centrifugal pumps
• B. Diaphragm pumps
• C. Gear pumps
• D. Piston pumps

Answer: (A)

The kind of fuel boost pump normally installed inside the fuel tanks is a centrifugal pump.

Centrifugal pumps use an impeller to add velocity to the fuel and generate flow with moderate pressure. Submerged in the tank, they provide steady, high-volume flow to feed the engine’s fuel system without needing complex priming, and their simple, compact construction is well suited for a pump that lives in fuel. This makes them reliable and easy to seal against fuel vapor and contamination, which is why they’re the standard choice for in-tank boost pumping.

Diaphragm, gear, and piston pumps are more specialized: diaphragm and gear/piston types tend to be used where higher pressure or positive-displacement action is needed, and they’re generally bulkier or more complex for in-tank use. They’re not as commonly chosen for the in-tank boost role, where continual, moderate flow from a submerged centrifugal design fits best.