Pumps commonly used as priming pumps are known as what type?

• A. A Centrifugal
• B. B Piston
• C. C Rotary Gear
• D. D Rotary Valve

Answer: (C)

Priming a pump hinges on creating suction strong enough to pull water into the pump, even when the suction line isn’t fully filled with water. A rotary gear pump is a positive-displacement device that traps water between intermeshing gears and moves it from the inlet to the outlet with tight tolerances. This design lets it bite into the suction, pull water up from the source, and clear air in the line, which makes it an effective and common priming pump on fire apparatus.

Centrifugal pumps, by contrast, rely on high-speed rotation to throw water outward and generally need water already present in the casing to start, so they’re not ideal for priming. Piston pumps and rotary valve pumps aren’t used as the standard priming pump on most apparatus due to practicality and general priming performance.