Fire pumps

Abstract

This chapter discusses the specifications and types of fire pumps. Fire pump is a term applied to pumps that provide the water to fire protection systems in buildings in case of a fire and/or to a fire hose main. The codes that must be met for these pumps are the NFPA-20 Code of the National Fire Protective Association in the case of North America which is enforced and interpreted through Factory Mutual (FM) and Underwriters Laboratory (ULF). Fire pumps are required when adequate water supply and pressure is not assured, such as the cases where a high-rise building had too high a static head required for the municipality water main, or the water supply pressure was not dependable. A fire pump must be rated at one of 21 ratings ranging from 25 to 5000 gpm in North America and at a pressure not less than 40 psi at zero suction pressure. The pump must produce 150% more than rated capacity at not less than 65% of the rated head with total shut off head not exceeding 140% of the rated head. The suction pipe for single or multiple pumps must be sized such that when all pumps are running at 150% capacity, the gauge pressure at the suction flange of the pump shall be no less than 0 bars.