Key Items for Multi-purpose Systems:
1. In duplex situations, where there is more then one dwelling unit, the designer will add 5 gpm to the sprinkler system demand to determine the size of the common piping and total water supply requirements.
2. Piping shall be listed and conform to the piping specifications listed in the standard. Piping that supplies only the plumbing fixtures shall comply with the local plumbing code and is not required to be listed.
3. The systems must be allowed by the local plumbing official. The installation company shall install a warning sign that indicates, “Warning, the water system for this home supplies fire sprinklers that require certain flows and pressures to fight a fire. Devices that restrict the flow or decrease the pressure or automatically shut off the water to the fire sprinkler system, such as water softeners, filtration systems and automatic shutoff valves, shall not be added to this system without a review of the fire sprinkler system by a fire protection specialist. Do not remove this sign.”
4. Any restriction of water through filtration systems is to be considered in the design.
5. An automatic bypass is to be installed in the water treatment equipment that directs all water to the system.
The 2002 edition included changes that established a minimum design discharge density. The requirements for multipurpose systems were changed to require a bypass valve for installations with water softeners or water filtration equipment installed and to update the requirements for network systems.
Residential sprinkler systems can be installed in many different ways. It is critical for first arriving firefighters to quickly size up the type of system, ensure the fire is extinguished (follow standard structure fire response protocol) and determine the best action with the system.
Part III will look closely at other systems and types.