Which type of stationary fire pump creates pressure by drawing water into an impeller?

The centrifugal type of fire pump is designed to create pressure by drawing water into an impeller, which is a rotating component that imparts velocity to the water. As the impeller spins, it generates kinetic energy that converts into pressure as the water exits the pump. This process relies on the principle of centrifugal force, where the water is accelerated outward and directed through the pump discharge.

Centrifugal pumps are favored in fire protection systems due to their ability to provide a consistent flow of water while efficiently handling varying supply conditions. They can operate effectively in a wide range of applications, making them suitable for both high-volume and moderate-pressure needs often found in fire suppression systems.

The other types mentioned, while also used in various pumping applications, do not operate by drawing water into an impeller in the same manner. Positive displacement pumps move water by trapping a fixed amount of liquid and forcing it into the discharge pipe, which is a different mechanism. Diaphragm pumps use a flexible diaphragm to create a vacuum and draw liquid in, and reciprocating pumps utilize a piston to move water in cycles. While all these pumps can be part of fire protection systems, the functioning principle of centrifugal pumps involving the impeller distinctly characterizes their operation.