American Fire Sprinkler Association 12750 Merit Dr., Suite 350 * Dallas TX 75251 Ph: (214) 349-5965 Fax: (214) 276-0908
--------------------------- TECHNICAL UPDATE JUNE 25, 2009 --------------------------- “We have a hospital that has a single water supply coming into the building and 6 vertical Class I standpipes with no fire pump. The height of the building varies between 4 and 7 stories. They want to comply with NFPA 25 requirement to have a flow test performed every five years on their standpipe system. NFPA 25 indicated that a flow test shall be conducted every 5-years at the hydraulically most remote hose connection of each zone of an automatic standpipe system to verify the water supply still provides the design pressure at the required flow. NFPA 14 indicates a standpipe system zone is a vertical subdivision of a standpipe system by height. Are we to test the 2 1/2 in. hose valve on each floor for the most remote standpipe, only the most remote 2 1/2 in. hose valve on the top floor of the most remote standpipe, the most remote hose valve of each standpipe riser or some other combination? What is the intent on NFPA 25 for flow testing standpipe systems?” We have reviewed NFPA 25, 2008 Edition as the applicable standard. Our informal interpretation is that a 5-year flow test is to verify the water supply still provides the design pressure at the required flow for automatic standpipe systems. The 2002 edition of NFPA 25 referenced testing the most remote hose connection. This has been misinterpreted by many to mean that the flow for only a single connection needs to be tested (which logic will not support since everyone knows the water supply adequacy relates to the system demand). The intent was clarified by the 2008 edition. Section 6.3.1.1 now states for flow tests, “A flow test shall be conducted every 5 years at the hydraulically most remote hose connections of each zone of an automatic standpipe system to verify the water supply still provides the design pressure at the required flow.” The words to stress in this section are “automatic standpipe system” since the flow test is only required for automatic systems. NFPA 14's definition of an automatic standpipe system is a standpipe systems that is attached to a water supply capable of supplying the system demand at all times and that requires no action other than opening a hose valve to provide water at hose connections. The standpipe system has to be flow tested for hydraulically calculated or pipe schedule designs and only if an automatic water supply is provided. The NFPA 25 Handbook indicates that the flow test is based on the calculated flow of 500 gpm for the most demanding riser and 250 gpm for each additional riser up to a maximum of 1250 gpm for buildings that are partially sprinklered and 1000 gpm for buildings that are fully sprinklered. As addressed by proposal 14-71 (ROP for next cycle), you perform two separate tests. One is for all the standpipes on the single highest floor to account for maximum elevation (assuming there are only two standpipes available). Then do a second test of the standpipes at the next highest story that allows the maximum flow, i.e. 1,250 gpm or 1,000 gpm when sprinklered on one level. So if the highest level that has four standpipes is on the 4th story that is where you do the second test. This is based on manual fire fighting being applicable to a single fire area. ----------------- Technical Update is prepared by the Technical Services Dept. of the AFSA: Vice President of Engineering and Technical Services Roland Huggins, a PE registered in fire protection engineering; Phill Brown, a NICET IV certified automatic sprinkler technician and NFPA Certified Fire Protection Specialist (CFPS) and Tom Wellen, a degreed fire protection engineering technologist. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. Copyright © 2009, American Fire Sprinkler Association. All Rights Reserved -------------------------- If you’d rather not receive future faxes from AFSA, fax your removal request to Amy Sweeney at Efax (214) 242-3155 or call toll free (888) 839-4830 or send e-mail request @ [email protected]. Please include your company name and the specific fax numbers(s) at which you do not wish to receive faxes from us. Our failure to comply with your request may be unlawful. _______________________________________________ Sprinklernotes mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklernotes
