What is a Fire Pump?
A Fire Pump is a part of a fire sprinkler system’s water supply and 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, such as UL or FM Global. The main code that governs fire pump installations in North America is the National Fire Protection Association’s NFPA 20 Standard for the Installation of Stationary Fire Pumps for Fire Protection.
Fire pumps function either by an electric motor or a diesel engine, or, 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.
How does a Fire Pump Work?
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.
When is a fire pump required?
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 operating pressure at the most remote location in order to provide a large volume of water, such as a storage warehouse. Fire pumps are also needed if fire protection water supply is provided from a ground level water storage tank.
If I have a fire pump, when should it be tested?
In between Annual tests, your equipment sits in the ‘off’ position. Many problems are invisible when pumps and controllers are sitting in a mechanical room and not running. Through simply running your equipment as part of a weekly test, many of the potentially serious problems can be discovered and addressed immediately.
Most fire pumps are either electric motor-driven, or diesel engine-driven, and the type and frequency of testing will vary depending on what you have in your building. For electric motor-driven fire pumps, we recommend at least running your equipment once a week for at least ten (10) minutes for a visual inspection and 30 minutes per week for diesel fire pumps.. You do not need to flow and measure water during this test — just witness the equipment running and have someone qualified present to address any problems that may arise. Some may point out that NFPA 25 allows for monthly testing in some circumstances, but we will always recommend a simple weekly test due to the importance of the equipment.
The fire pump flow test is required by NFPA 25 to be conducted once a year in order to measure the pump’s flow and pressure. The test should be performed by attaching hoses to the discharge test header. The hoses are run to a safe location where the flow of water will cause no damage. Pressure readings are taken as the pump is run through its various stages. At I.F. Wilson Fire Protection Ltd, the results are recorded and plotted on a graph by our engineering department. These test results are compared to the factory specifications and the test results from previous years. If there is a significant reduction in the pump’s performance, further examination is needed to make the necessary repairs.