A
fire pump is a part of a
fire sprinkler
system's water supply and can be powered by electric, diesel or steam.
The pump intake is either connected to the public underground water
supply piping, or a static water source (e.g., tank, reservoir, lake).
The pump provides water flow at a higher pressure to the sprinkler
system
risers and hose standpipes. A fire pump is tested and
listed for its use specifically for fire service by a third-party testing and listing agency
Operation
Fire pumps may be powered either by an
electric motor or a
diesel engine, or, very occasionally a
steam turbine.
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. Alternately, other
fire hoses reels or other firefighting connections are opened, causing a pressure drop in the fire fighting main.
Fire pumps are needed when the local municipal water system cannot
provide sufficient pressure to meet the hydraulic design requirements of
the fire sprinkler system. This usually occurs if the building is very
tall, such as in
high-rise
buildings, or in systems that require a relatively high terminal
pressure at the fire sprinkler in order to provide a large volume of
water, such as in storage warehouses. Fire pumps are also needed if fire
protection water supply is provided from a ground level water storage
tank.
Types of pumps used for fire service include: horizontal split case,
vertical split case, vertical inline, vertical turbine, and end suction
Jockey Pump
A jockey pump is a small pump connected to a fire sprinkler
system and is intended to maintain pressure in a fire protection piping
system to an artificially high level so that the operation of a single
fire sprinkler will cause a pressure drop which will be 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.
