Bob, Just my read. Here's the commentary material. You can judge the intent for yourself.
Lateral sway bracing is addressed in 9.3.5.3. For branch lines and piping smaller than 2 1/2", bracing is not required. Branch lines 2" in diameter and smaller are considered to have sufficient flexibility to avoid damage under their own momentuym. Mains. however, can also carry the loads of adjacent branch lines and must be braced, regardless of size. A change included in the 2007 edition of NFPA 13 clarified that bracing is not required on 2 1/2" starter pieces, that is, the first sections of pipe on branch lines from a cross main, provided they do not excedd 12 feet in length. It should also be noted that, where high siesmic loads are expected, bracing may be required for barnch lines less than 2 1/2" in diameter to reuce the zone of influence for the brace. I left in Mister Dubay's use of the passive voice without edit ( but not without comment) although i did excise the metric equivalents and a reference to zone of influence. All else is verbatim. On Wed, May 6, 2009 at 2:35 PM, Bob Knight <[email protected]> wrote: > Ron, > > Thanks, I knew that it was for branch lines only, but I wasn't sure if it > could be extended to a larger size branch line. I don't have a handbook, > gotta get one one of these days, so it sounds by your posting that the > handbook is stating that it is limiting this exception to 2-1/2". I just > thought that this had come up once before and that it had been determined > that this could be extended to larger piping. Guess I was mistaking since I > couldn't find anything in the archives. > > > > Thanks, > > > > Bob > > > > -----Original Message----- > > From: [email protected] > [mailto:[email protected]] On Behalf Of Ron Greenman > > Sent: Wednesday, May 06, 2009 3:14 PM > > To: [email protected] > > Subject: Re: 2-1/2" Starter Pieces > > > > Bob, > > > > I'd say that because the 'exception" is so specific (2 1/2 in starter > > pieces less than 12' long) that the intent was also specific and, in > > addition, because they used starter pieces as a criteria they mean > > only for branch lines. I think the handbook commentary for 9.3.5.3.3 > > suggests that it is a gimme for this single set of conditions. > > > > On Wed, May 6, 2009 at 2:02 PM, Bob Knight <[email protected]> wrote: > >> NFPA 13 9.3.5.3.3 States, "The requirements of 9.3.5.3.1 shall not apply > to > >> 2-1/2" starter pieces that do not exceed 12' in length". Is this section > >> limiting this to 2-1/2" piping or can it be assumed that starter pieces of > >> larger pipe sizes can also be included? > >> > >> Thank you, > >> > >> Bob Knight, CET > >> (208) 318-3057 > >> [email protected] > >> www.firebyknight.com > >> > >> > >> _______________________________________________ > >> Sprinklerforum mailing list > >> http://lists.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) > >> > > > > > > > > -- > > Ron Greenman > > at home.... > > > > _______________________________________________ > Sprinklerforum mailing list > http://lists.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) > -- Ron Greenman at home.... _______________________________________________ Sprinklerforum mailing list http://lists.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)
