Why we can't use a normal water pump for fire fighting?
2025-11-27
Differernce between fire pump and normal water pump: 1: The system is totally different Normal water pump's system is under control by discharge valve to running at best efficiency point area Fire pump's system is a free system, the discharge valve and suction valve are fully open anytime, as we don't know when the fire will be come 2: Normal water we know the duty point and pump will be runnig at this duty point too (Usually is near the best efficiency point) Fire pump we only have the design point, but we can't predict the exact point on the curve when the fire pump will be running during a fire. Therefore, we must ensure the fire pump operates safely at any point on the full curve (Including the area where the flow exceeds 1.5Q) 3: The power curve is totally different UL/FM and NFPA20 standards require the pump suppliers to provide the fire pump curve with the full range of flow and powercurve showing the Max BHP(Brake Horsepower) Additionally, when the driver power bigger than the Max BHPof the fire pump, you can running the pump safely under any condition of pump load. For the same design point pump, who have lower Max BHP, who will get lower cost for their fire pump's package
1: The system is totally different
Normal water pump's system is under control by discharge valve to running at best efficiency point area
Fire pump's system is a free system, the discharge valve and suction valve are fully open anytime, as we don't know when the fire will be come
2: Normal water we know the duty point and pump will be runnig at this duty point too (Usually is near the best efficiency point)
Fire pump we only have the design point, but we can't predict the exact point on the curve when the fire pump will be running during a fire. Therefore, we must ensure the fire pump operates safely at any point on the full curve (Including the area where the flow exceeds 1.5Q)
3: The power curve is totally different
UL/FM and NFPA20 standards require the pump suppliers to provide the fire pump curve with the full range of flow and powercurve showing the Max BHP(Brake Horsepower)
Additionally, when the driver power bigger than the Max BHPof the fire pump, you can running the pump safely under any condition of pump load.
For the same design point pump, who have lower Max BHP, who will get lower cost for their fire pump's package