A fire pump is a part of a fire sprinkler system's water supply and powered by electric, diesel or steam. The pump intake is either connected to the public underground water supply piping, or a static water source (e.g., tank, reservoir, lake).
Fire pumps function either by an electric motor or a diesel engine, or, occasionally a steam turbine. If the local building code requires power independent of the local electric power grid, a pump using an electric motor may utilize, when connected via a listed transfer switch, the installation of an emergency generator.
Fire pumps are needed when the local municipal water system cannot provide sufficient pressure to meet the hydraulic design requirements of the fire sprinkler system. This usually occurs if the building is very tall, such as in high-rise buildings, or in systems that require a relatively high terminal pressure