|
Fire pumps may be powered either by an electric motor or a diesel engine. If the local building code requires power independent of the local electric power grid, a pump using an electric motor may utilize, when connected via a listed transfer switch, the installation of an emergency generator.
The fire pump starts when the pressure in the fire sprinkler system drops below a threshold. The sprinkler system pressure drops significantly when one or more fire sprinklers are exposed to heat above their design temperature, and opens, releasing water or alternatively when other firefighting connections are opened, causing a pressure drop in the fire fighting main.
Types of pumps used for fire service include: horizontal split case, vertical split case, vertical inline, vertical turbine, and end suction.
A jockey pump is a small pump connected to a fire sprinkler system in parallel with the fire pump. It maintains pressure in a fire protection piping system to an artificially high level so that the operation of a single fire sprinkler will cause an appreciable pressure drop which will be easily sensed by the fire pump automatic controller, causing the fire pump to start. The jockey pump is essentially a portion of the fire pump's control system. The main code that governs fire pump installations in North America is the National Fire Protection Association's (NFPA) NFPA 20 Standard for the Installation of Stationary Fire Pumps for Fire Protection.
|