Doubling the speed of a fire pump requires the horsepower to increase by how much?

Doubling the speed of a fire pump significantly affects the horsepower required to operate the pump due to the relationship between speed, flow rate, and horsepower. In pump systems, power (horsepower) is proportional to the cube of the speed. This means that if the speed is doubled, the horsepower requirement increases by a factor of eight (2^3 = 8).

Therefore, when the speed of the fire pump is increased twofold, the horsepower needed to maintain that performance does not just double, but rather increases exponentially. This principle is rooted in fluid dynamics, where pump performance is influenced by the velocity of the fluid being moved. The cubic relationship underscores the importance of understanding pump characteristics and requirements in fire protection systems, ensuring adequate water flow and pressure during emergencies.