Hose Valves in Horizontal Exits
“We are currently designing a six-story apartment building with multiple horizontal exits (three-hour-rated fire walls in the corridors). When designing a Class 1 standpipe, a hose connection shall be provided on each side of the wall adjacent to the exit opening of horizontal exits (7.3.2.2 NPFA 14 2016 edition). There are exceptions to this rule in 7.3.2.2.1 where if all floor areas are reachable within the allowable distance, from an exit stairway hose connection on each side of the horizontal exit then you’re not required to provide hose connections on each side. This requirement is similar to the International Building Code’s requirements in section 905.4(2) except the IBC 2015 edition only allows 100 ft of hose with a 30-ft reach from the nozzle to a horizontal exit compared to 200 ft in a sprinkler building per NFPA 14. My question is, if only one side of the horizontal exit can be reached from a hose connection in a stairway, is a hose connection required on each side of that horizontal exit or can you eliminate the one on the side you can reach and only add an additional hose connection on the side of the exit you can’t reach from the stairway?” We have reviewed NFPA 14, 2016 edition that you indicated as the applicable standard as well as the IBC, 2015 edition. Our informal interpretation is it is acceptable to delete the hose connection from only one side of a horizontal exit. We need to determine if you can eliminate the hose valve on the side of the horizontal exit that can be reached from an adjacent hose valve. IBC section 905.4(2) states a hose connection shall be provided “On each side of the wall adjacent to the exit opening of a horizontal exit. “The exception states “Where floor areas adjacent to a horizontal exit are reachable from an interior exit stairway utilizing a hose connection with a stream of 30 ft. with a hose of 100 ft., a hose connection shall not be required at the horizontal exit.” Now NFPA 14 section 7.3.2.2* states: “Hose connections shall be provided on each side of the wall adjacent to the exit openings of horizontal exits.” The exception listed in 7.3.2.2.1* states: “Where all floor areas are reachable from an exit stairway hose connection on the same side of a horizontal exit within the distances required by 7.3.2.2.1.1 or 7.3.2.2.1.2 as applicable, the hose connection on the other side of the horizontal exit shall be permitted to be omitted.” The IBC is a little ambiguous but correlates with the more explicit NFPA 14 criteria. It says the connection can be deleted from the OTHER side of the horizontal exit. So clearly either one or both connections can be omitted. The reason it is the other side away from the stairway being measured to is that the fire department needs to be in a relatively safe area in order to access the hose connection and to make preparations to attack the fire. This requires being separated from the fire-by-fire rated construction (just like being in an adjacent stairwell). Where you have a potential problem is that the standard and the code don’t coincide with each other. As already stated, the IBC only allows a maximum of 130 ft from a stairwell to the horizontal exit. NFPA 14 7.3.2.2.1.1 on the other hand states “The travel distance in 7.3.2.2.1 shall be 200 ft (61 m) for sprinklered buildings.” Section 7.3.2.2.1.2╙ states “the travel distance in 7.3.2.2.1 shall be 130 ft (39.7 m) for nonsprinklered buildings.” This is where it can be confusing due to the code and standard using different requirements (no allowance for sprinklered buildings). There are actual two items. NFPA states a maximum travel distance, where the IBC states a hose length with a distance for the throw of the hose. This is a nuance that can impact the outcome but is minor compared to the overall difference in distance for sprinklered buildings. Since a code supersedes a standard, the IBC 100 ft plus a 30-ft throw is the allowed distance. Having said that, there is an inherit conflict in the IBC on maximum distance from connections when compared to stairwells. IBC section 905.4(6) states: “Where the most remote portion of a nonsprinklered floor or story is more than 150 ft. away from a hose connection or the most remote portion of a sprinklered floor or story is more than 200 feet from a hose connection, the fire code official is authorized to require that additional hose connections be provided in approved locations.” This section coincides with the distance defined in NFPA 14. It’s reasonable to apply the longer distance defined in NFPA 14 for horizontal exits based on this section of the IBC regarding overall distance from stairwells. After all, a horizontal exit is fundamentally functioning as another stairwell. Naturally, this will require approval of the AHJ. Hopefully we can get the code and standard on the same page during the next revision cycles. ========= 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 and Tom Noble E.T., a Technical Programs Specialist. 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 2017, American Fire Sprinkler Association. All Rights Reserved. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.firesprinkler.org/private.cgi/sprinklernotes-firesprinkler.org/attachments/20170410/71784524/attachment.htm>
