American Fire Sprinkler Association 12750 Merit Dr., Suite 350 * Dallas TX 75251 Ph: (214) 349-5965 Fax: (214) 276-0908
----------------- TECHNICAL UPDATE August 25, 2010 ----------------- “An engineer indicated that a lateral brace is required within 6 ft of each elbow on a feed or cross main when the main makes a turn. If a feed or cross main turns, is this the end of a main or is it when a feed or cross main end at a cap?” We have reviewed NFPA 13, 2010 Edition as the applicable standard. Our informal interpretation is that a brace is not required within 6 ft of each elbow on a feed or cross main. Section 9.3.5.3.5 does not apply to this application since it indicates that the distance between the “last brace” and the end of the pipe shall not exceed 6 ft. The commentary for this section in the handbook indicates that last brace within 6 ft of the end of the main eliminates the potential for a large cantilevered load caused by branch lines beyond the last brace. Since this application is an offset or turn in the main, the braces will not likely be the “last brace” on the main. Section 9.3.5.11.2 specifically addresses braces at offsets and turns in the mains. This section indicates that when each run of pipe between changes in direction shall be provided with both lateral and longitudinal bracing, unless the requirements of 9.3.5.11.3 are met. Section 9.3.5.11.3 is an exception to clarify that pipe runs less than 12 ft in length shall be permitted to be supported by the braces on adjacent runs of pipe. The commentary for this section from the handbook indicates that short runs of main do not require bracing if their loads can be assumed by adjacent piping runs. Thus, if the offset pipe run or turn is less than 12 ft in length, additional bracing is not needed. If the offset or turn pipe run length is greater than 12 ft, then longitudinal and lateral bracing is required on the pipe run according to 9.3.5.11.2. ------------------ Technical Update is prepared by the Technical Services Dept. of the AFSA: Roland Huggins, a PE registered in fire protection engineer, Vice President of Engineering and Technical Services; 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 © 2010, 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://fireball.firesprinkler.org/mailman/listinfo/sprinklernotes
