Paul, I haven't had time to look up the distinction in my -13 yet today, but I would think the application and design of them would preclude them being confused.
A pipe hanger is designed to hold the piping and sprinklers in place against the force of gravity, or so I'm told. It's resistance to movement of the fire sprinkler system is in the vertical plane, and although there are applications where it can be installed at an angle for pitched roofs, the intent is the same. Seismic bracing has nothing to do with supporting the pipe against gravity, as the movement it is attempting to resist is all in the horizontal plane - both lateral and longitudinal - and the forces acting on braces aren't required to provide resistance to gravity, not in -13, not in ASCE7, not in any of the books detailing structural engineering. Ask yourself this - if I took the seismic bracing off the system, would it fall to the ground without an earthquake? The answer of course is no, and this is demonstrated by the lack of any requirement in ASCE7 for seismic bracing in seismic design category A or B. Conversely, if you removed the pipe hangers, and just left the seismic bracing, would the pipe stay in place? Again, of course, the answer is no. I don't have a code reference, other than some structural engineering books I've had to read sections of in order to understand seismic issues. -- PARSLEY CONSULTING Ken Wagoner, SET 760.745.6181 voice 760.745.0537 fax [email protected] <mailto:[email protected]> e-mail www.ParsleyConsulting.com <http://www.ParsleyConsulting.com> website IMPORTANT NOTICE: This correspondence is not a Formal Interpretation issued pursuant to NFPA Regulations. Any opinion expressed is the personal opinion of the author and does not necessarily represent the official position of the NFPA or its Technical Committees. In addition, this correspondence is neither intended, nor should it be relied upon, to provide professional consultation or services. Gobeli, Paul wrote: > Where in NFPA 13 or elsewhere does it state that a seismic brace is not a > pipe hanger? I seem to recall this stated explicitly somewhere but cannot > place it. > > Paul Gobeli, CET > Fire Protection System Designer > Minneapolis - St. Paul Office > Burns & McDonnell :: Engineering :: Architecture > 8201 Norman Center Drive, Suite 300 > Bloomington, MN 55437 > P: 952.656.6003 Ext 3645 :: F: 952.229.2923 > www.burnsmcd.com<http://www.burnsmcd.com/>/minneapolis > > Atlanta :: Chicago :: Houston :: Kansas City :: Miami :: Minneapolis :: New > Jersey :: St. Louis :: Washington D.C. > Proud to be one of FORTUNE's 100 Best Companies To Work For > P Please consider the environment before printing. > > This e-mail and any attachments are solely for the use of the addressed > recipients and may contain privileged client communication or privileged work > product. If you are not the intended recipient, and receive this > communication, please contact the sender by phone at 952-656-6003x3645 and > delete and purge this e-mail from your e-mail system and destroy any other > electronic or printed copies. Thank you for your cooperation. > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > > _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
