Which of the following is NOT a type of fire pump?

The correct choice indicates that a hybrid pump is not categorized as a type of fire pump. Fire pumps are specifically designed to deliver water at elevated pressures to provide fire protection. They are typically classified into several established types based on their operation mechanism and application.

Centrifugal pumps are widely used in fire protection systems due to their high flow rates and efficiency in moving water; they operate based on the centrifugal force generated by a rotating impeller. Piston pumps are also common in certain fire suppression systems, especially where high pressures are essential, as they use a reciprocating mechanism to move water. Rotary gear pumps, although less common, can be utilized where specific operational requirements necessitate their design for driving water flow and creating pressure.

Hybrid pumps, however, do not conform to a standard classification within the context of fire pumps. They may combine features of different types of pumps, but they are not recognized specifically as fire pumps in conventional fire protection terminology. Thus, this distinction is what confirms that it is not a type of fire pump as understood in the context of fire safety and suppression systems.