A fire pump is usually a part of a large building fire sprinkler system and is connected to the municipal water system at the intake and to the buildings sprinkler system risers at the discharge. Fire Pumps are usually powered by an electrical motor and may require the installation of an emergency generator. Other means of power are a directly connected diesel engine, or in rare cases, a steam turbine.

The fire pump becomes active when the pressure in the fire sprinkler system drops below a threshold. The sprinkler system pressure drops significantly when one or more sprinkler heads are exposed to heat above their design temperature. The sprinkler head releases and water discharges.

The discharge of water triggers a water flow alarm inside the sprinkler system pipes, which is monitored by a central station and which the Fire Department responds to. The fire pump provides additional water pressure to the sprinkler system.
Fire pumps are required in high-rise buildings. They are also used in warehouses and facilities that do not have adequate city water pressure. In this case, a fire water tank is used.