The fire water pump is the heart of a fire truck. It is the mechanism that delivers a fire stream at a precise pressure and flow for successful extinguishment of any type of fire. The heart of the pump is the impeller shaft assembly, which is designed for optimum performance and longevity. To achieve this, a fire pump should be equipped with flame plated impellers. The flame plating process involves adding tungsten carbide to the wear surfaces of the pump’s impeller. The result is a hard, durable coating that outwears chrome, hard chrome-plated, and tool steel. Flame plated impellers also eliminate 75% of the internal pump wear.
The first step in choosing the right fire pump is to determine how much flow you need to get the job done. You can do this by comparing the fire suppression system’s gallons-per-minute (gpm) requirement to the hydrant flow test data. Then, look at the power curve on the factory-certified test report to see how high it peaks and when it begins to drop. If the power curve continues to climb, your pump might be undersized.
Another consideration is the building’s elevation. The fire suppression system designer needs to take into account the effects of gravity, which require more pressure to push water to sprinklers on higher floors. The building’s occupancy classification should also be taken into account. If the building has a hazardous use, for example, the fire safety professional will need to know how much gpm it requires at 125-psi static pressure. This information will help the fire suppression system designer select the right size pump.