The fire water pump is the heart of the system that will deliver the flow and pressure needed to fight your facility’s fires. It is critical to understand that the fire water pump must be sized and specified correctly or the results could be disastrous in the event of a fire. Too little and you’ll waste resources, too much and you risk a loss of life and your valuable assets. It’s much like Goldilocks finding the perfect bowl of porridge or the best bed for a nap, you want to find that sweet spot that is safe, efficient and code compliant.
The first thing to look at when selecting a fire water pump is the amount of water required for the system. To do this, it’s important to consider the fire sprinkler area calculations and NFPA 14 Standard for the Installation of Standpipes and Hose Systems, which requires that a building have a certain amount of water volume in case a fire is detected.
Using these calculations, you can determine how large of a fire water pump is required for the system based on the total area of the building and the highest hazard level present. For example, if the area is classified as Light Hazard then you would require 500 gpm while areas classified as Ordinary Hazard 1 would require 250 gpm.
Once you know how much water is required, you can use the pump’s horsepower curve found on the factory-certified test report to determine what size of a driver it will need. The driver must be sized to meet the horsepower demands at the peak of the power curve, but not so large that it is oversized which would violate UL and FM requirements.