May 15, 2019 by Anthony Jaspal, PE, CPD, Plumbing Practice Area Leader
A fire pump is a critical component of a building’s water-based fire protection system. In an actual emergency, without an operating fire pump, the associated fire protection system will at best provide only a measure of safety and will not achieve the results of the code-required, engineered, and installed design.
When we discuss a fire pump we are typically referring to the assembled unit, consisting of: the fire pump, driver (commonly an electric motor), controller, and attendant accessories.
Three of the major entities and publications that impact fire pump installations are:
- National Fire Protection Association (NFPA) – Standard 20: Installation of Stationary Pumps for Fire Protection
- International Code Council (ICC) – International Building Code (IBC)
- Local Authority Having Jurisdiction (AHJ) – typically a City or County Fire Marshal and the local fire code requirements
While there are numerous considerations with regards to fire pump positioning and installation within a building, per NFPA 20 and the IBC some major items to remember include:
- The location of and access to the fire pump room must be pre-planned with the fire department. Because most fire departments have procedures requiring operation of a fire pump unit during an incident, building designers should locate the pump room to be easily accessible.
- Fire pump rooms must be free from storage, equipment and penetrations not essential to the operation of the pump and related components.
- One specific exception is equipment related to domestic water distribution, which can be located within the fire pump room. Typical examples of such equipment include booster pumps and hydro-pneumatic tanks.
- Otherwise, equipment that increases or creates an additional fire hazard and is unrelated to the fire protection system is not to be located within the fire pump room. Typical prohibited examples include boilers and fuel-fired water heaters.
- The fire pump room must be properly sized to fit all the components necessary for pump operation and to accommodate:
- Installation and maintenance clearances.
- Clearances for energized electrical equipment per NFPA 70 (National Electrical Code).
- Proper orientation of the pump relative to the suction piping to ensure established minimum distances to parallel fittings.
- If a fire pump room is not directly accessible from the outside it shall be accessible through a fire-resistant rated corridor from an enclosed stairway or exterior exit.
- The pump room must be provided with a door and unobstructed passageway large enough to allow removal of the largest piece of equipment.
- Fire pumps shall be located within rooms that are separated from all other areas of the building by two-hour fire barriers or horizontal assemblies constructed per the IBC. In other than high-rise buildings, this can be reduced to a one-hour requirement if the building is equipped throughout with an automatic sprinkler system.
- Provisions much be made to both ventilate and heat the pump room, the latter to ensure no less than 40 degrees Fahrenheit is maintained.
- At least one floor drain must be provided and floors shall be pitched for adequate drainage of escaping water from critical equipment.
- The fire pump components, water supply, and power supply shall be protected against possible interruption through damage by explosion, fire, flood, earthquake, vermin, windstorm, freezing, vandalism, and other adverse conditions.
- While NFPA 20 does not specifically prohibit below grade installations, it raises a “caution flag” and indicates that special consideration must be given to drainage and flooding concerns for any such potential fire pump installations.
- Where the water supply (commonly a city water main) is of sufficient pressure to be of material value without the pump, the fire pump shall be installed with a bypass.
- This bypass is to be a normally open pathway so that the water supply is automatically available to the building system in the event the fire pump fails to start.
- This bypass therefore requires valves (commonly a double check valve backflow preventer) to ensure the intended one-way direction of flow.
- This bypass is to be as least as large as the required fire pump discharge pipe.
- Because this bypass and associated valves can be of significant physical size, this is yet another space-planning consideration for the fire pump room.
In summary, a fire pump is a critical life-safety equipment item in a building. Numerous requirements and factors must be considered for such installations. Therefore, an early and direct dialog amongst the building owner, architect, MEP engineer, local fire marshal, and fire protection contractor (if party to the planning and design) is of utmost importance to ensure a well-planned and compliant final installation.
Anthony Jaspal, PE, CPD
Plumbing Practice Area Leader