May 9, 2016
Rods Less Than 6 in. to Omit Lateral Bracing “Section 9.3.5.5.10 indicates that pipe individually supported by rods less than 6 in. from the point of connection to top of pipe does not require lateral sway bracing. However, the Automatic Sprinkler Systems Handbook indicates that the 6 in. rod rule doesn't apply to feed mains and cross mains and must be lateral braced regardless of rod length. Is it required to laterally brace all feed mains and cross mains with rods less than 6 in.? Does a 2-1/2-in. or 3-in. branch line that is supported with rods less than 6 in. long measured between the top of the pipe and the point of attachment to the building structure require lateral bracing or is it exempted by section 9.3.5.5.10?” We have reviewed NFPA 13, 2013 edition that you indicated as the applicable standard as well as the 2016 edition. Our informal interpretation is that the text in the handbook is an error and should not be applied. Section 9.3.5.5.10 states, “The requirements of 9.3.5.5 shall not apply to pipes individually supported by rods less than 6 in. long measured between the top of the pipe and the point of attachment to the building structure.” There is no other supporting information excluding cross mains and feed mains from this section. As such, the handbook text addressing Section 9.3.5.5.10 is incorrect that states, “For the 2013 edition, cross mains as defined in 3.5.5 cannot use this exception and will need lateral braces even if short hangers are used. The concern is that if the lateral sway braces are omitted, then the hangers in this situation would have to carry the load of the main and the attached branch lines, which in many applications could be a tremendous horizontal force.” The 2016 edition of the Automatic Sprinkler Systems Handbook removed the text that was in the 2013 handbook commentary regarding this subject area is not valid and should not be applied. The disclaimer provided in the front of the handbook under the heading Notice Concerning Code Interpretations that states, “The commentary and supplementary materials in this handbook are not a part of the NFPA Document and do not constitute Formal Interpretations of the NFPA (which can be obtained only through requests processed by the responsible technical committees in accordance with the published procedures of the NFPA). The commentary and supplementary materials, therefore, solely reflect the personal opinions of the editor or other contributors and do not necessarily represent the official position of the NFPA or its technical committees.” ------------ 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. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.firesprinkler.org/private.cgi/sprinklernotes-firesprinkler.org/attachments/20160509/a3d15ada/attachment.htm>
