Fire-Flow from Hydrants
“I have four private fire hydrants planned to be installed. The local requirement says the minimum required fire-flow for each required private fire hydrant shall be 1,000 gpm where all buildings on the same property are protected by an approved automatic sprinkler system. Since the location has four fire hydrants, does this mean that 1,000 gpm is flowing from each hydrant simultaneously for a total of 4,000 gpm?” We have reviewed the International Fire Code, 2015 edition, as amended, as the applicable code. Our informal interpretation is that the fire-flow for each individual hydrant shouldn’t be combined to flow simultaneously. The amendment as indicated above indicates that each fire hydrant shall be capable of flowing 1,000 gpm. This is not saying to combine the flows from each fire hydrant and flow them simultaneously. As such, the minimum flow from the hydrant is evaluated for each individual hydrant where the water supply test data results are taken to the 20-psi residual pressure. If the owner elected to install additional hydrants, the water supply system may not support the simultaneous flow of 1,000 gpm from each hydrant. Thus, the requirement for simultaneous flow from all fire hydrants is flawed. The correct determination of the fire-flow requirements for buildings is from Tables B105.2 and B105.1(2). The enforceable text does not indicate whether the flow comes from public mains, private mains, well and pump, or any other type of water supply. The code indicates the minimum amount of water measured at 20-psi residual pressure that is available for firefighting per the definition of fire-flow in B102. The water supply data should be taken to the 20-psi mark to show the available flow available for firefighting. In addition, the water supply ╥system╙ needs to provide the flow and can be accomplished using multiple water supply mains and hydrants. A former staff member of the ICC (who had responsibility for Appendix B) also confirmed this interpretation. ------------ Technical Update is prepared by the Technical Services Dept. of the AFSA: Roland Huggins, a PE registered in fire protection engineering, Vice President of Engineering and Technical Services; and Tom Wellen, a PE registered in fire protection engineering. 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 2016, American Fire Sprinkler Association. All Rights Reserved. Ada Dickson Ada Dickson Administrative Assistant Technical Services Dept. PH: (214) 349-5965 ext. 124 Fax: (214) 343-8898 E-mail: [email protected] -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.firesprinkler.org/private.cgi/sprinklernotes-firesprinkler.org/attachments/20161107/171408d0/attachment.htm>
