A fire water pump is a special type of hydraulically powered pump that is used to increase the hydraulic pressure at a point where the demand for fire suppression systems like automatic sprinklers, standpipes, and foam systems cannot be met through normal supply lines. These pumps can be installed on the ground, in a pit or on a truck, making them portable and easy to maneuver when needed for emergencies.
Typically, these systems are installed when the existing water supply line cannot provide enough hydraulic pressure to meet the demands of the fire protection system or when a building has a very high elevation change that limits water flow from the main supply. It’s important to have an understanding of the operating principles, types and drivers for fire water pumps so that they are properly sized to meet their intended use.
The power to drive the pumps can be supplied by electric motors, diesel engines or steam turbines. Those that have an electric motor take electrical energy from a utility connection or generator and use it to spin the shaft of the fire water pump, which then provides pressure to the system. When selecting an electrical motor for your fire water pump, look at the factory test report to see if the motor is capable of meeting the requirements of NFPA 20. You’ll want to select a motor that has a constant rising power curve or one that meets the end of the head and flow curves, which is based on the specific pump hydraulic design.