What type of pump is most commonly used as a priming device on modern fire pumps?

The most commonly used type of pump as a priming device on modern fire pumps is the positive displacement pump. This is due to its ability to efficiently remove air from the pump and the suction hose, thereby creating a vacuum that allows water to be drawn into the system. Positive displacement pumps operate by trapping a fixed amount of fluid and forcing it into the discharge line, which makes them particularly effective for priming.

When it comes to fire operations, quick and reliable priming is crucial to ensure that water can be delivered to the fire quickly, and positive displacement pumps excel in this regard. They can generate a vacuum even when the pump is partially submerged, which increases their effectiveness in various conditions faced during firefighting.

Other pump types, such as rotary pumps and validation pumps, may have their specific applications in the fire service but do not offer the same efficiency and effectiveness in priming as positive displacement pumps. Gravity pumps rely on the force of gravity to move liquids and might not be suitable for creating the necessary suction needed for priming fire pumps.