NFPA 20, Standard for the Installation of Centrifugal Fire Pumps. A fire pump is a fixed pump that supplies water to a fire suppression system. The main purpose of a fire pump is to increase the water and pressure that flows through it into the fire suppression system. Since systems require a minimum amount of water and pressure to meet fire codes, a fire pump is required to increase the amount of water and pressure that is supplied from sources such as elevated or in-ground storage tanks and even municipal water supply mains or reservoirs. There are three main types of fire pumps used in these systems: Horizontal Shaft, Vertical Shaft, and Vertical Turbine. Along with the fire pumps there are other things included in the pump systems such as the pump drivers, the pump controller and testing equipment.
             Out of the three types of pumps mentioned in the previous paragraph, the horizontal shaft pump, also known as the horizontal split-case pump, is the most common type found in fixed systems. The shaft on this pump sits horizontally with the pump on one side and the driver on the other. This pump is not a self-priming pump so it can't be used to supply water from a static source it must use water supplied from a pressurized water source like water supply mains. Water is drawn into the pump and forced back out through the use of centrifugal force. Water flows through vanes on an impeller inside the pump casing and is then discharged into the piping of the fire suppression system. These systems can be single-stage or multistage, multistage being more than one impeller on the shaft. The most common types of these pumps can flow between 500-1500 gallons per minute (gpm). There are pumps that can flow anywhere from 150gpm up to 4500 gpm.
             The vertical shaft pump is similar to the horizontal shaft pump except the impeller sits vertically. In this style of pump the impeller is always driven by an electric motor that sit...