Fire Pumps

What is a fire pump?

A type of pump used to move water through a fire sprinkler system or to manual hose bibs in a commercial building or industrial plant. The pump’s intake is usually connected to the external water supply, although in some cases it may be connected to a local water source such as a well, tank, or body of water.

The fire pump system, of which the pump is the critical component, is designed to quickly deliver enough water to efficiently douse a fire before it has a chance to spread. In many areas, they are required to be periodically tested and certified by the local fire inspection agency. They are commonly used in buildings with upper floors that are too high to be reached with the pressure of the local water supply, or where there is not enough fire fighting capacity from the local water supply.

They generally work within the following ranges:

• Flow rate ranges between 20 and 5,000 gpm
• Total head (pressure) ranges between 100 and 1,200 ft
• Horsepower ranges between 10 and 800 hp

Fire pumps and the rest of the system are required to meet the requirements of NFPA (National Fire Protection Association), UL (Underwriter’s Laboratory), and, in Canada, CSA (Canadian Standards Association). These requirements are quite detailed as to both the hydraulic and the mechanical requirements for the pump, driver, and controls. There are a limited number of NFPA, UL, and CSA approved pump suppliers. Local standards and the owner’s insurance requirements should be studied carefully before selecting a fire pump type and supplier.

How do they work?

They are usually centrifugal pumps and are powered by either an A.C. electric motor or a diesel engine. When one of the sprinklers in the building detects a high level of heat, the pump begins working immediately. In some cases, the fire regulations may require a fire pump to have an emergency generator as a back-up in the event of a power failure. Small, portable engine-driven configurations are used in forest fire fighting applications.

Fire pump mechanisms

The most common types are horizontal split case pumps and vertical turbine pumps. Some applications for lower flows may include end suction pumps or vertical inline pumps. Many fire systems also use a jockey pump. This is a small centrifugal pump that runs continuously to keep the fire system piping filled and under pressure. This ensures that the sprinklers will be immediately effective when they are opened and the fire pump is started.