The past and current editions of NFPA 409 do not specifically address the spacing in 25 ft bays. A proposal was made in the F2009 Report of Proposals in 409-18, Log #13 to add a new sentence for clarification in the next edition. It stated, “In buildings with storage bays 25 ft wide, 12 ft 6 in. shall be permitted." The committee action as Accept in Principle and to refer to NFPA 13. The problem in NFPA 13 is that there is no reference to hazard classification of aircraft hangers. A comment was made in F2009 Report on Comments to revert back to the original proposal and the committee agreed with “Accept” in 409-5, Log #8. The 2011 Edition of NFPA 409 is pending approval at the NFPA annual meeting floor vote in June, 2010. Since the document has not been approved, you are subject to the approval of the AHJ to use the new language. There does not appear to be any NITMAMs on this particular issue.
Tom Wellen On Feb 25, 2010, at 2:01 PM, Chris Cahill wrote: > Yeah but 6.2.4.3 for the closed head system sends you to 6.2.2.3. > Granted > this is under the heading for deluge foam but the relevant section > sends you > there so it's enforceable. And anything specific in 409 that > conflicts with > 13 overrides 13. So as I see it you will have 3 lines in a 25' bay. > > Chris Cahill, P.E. > Fire Protection Engineer > Sentry Fire Protection, Inc. > > 763-658-4483 > 763-658-4921 fax > > Email: [email protected] > > Mail: P.O. Box 69 > Waverly, MN 55390 > > Location: 4439 Hwy 12 SW > Waverly, MN 55390 > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Thom > McMahon > Sent: Thursday, February 25, 2010 1:41 PM > To: [email protected] > Subject: RE: Aircraft Hangar Question of the Day! > > 6.2.4 Closed-Head Water Sprinkler Systems for Aircraft Storage > and Servicing Areas. > 6.2.4.1" Sprinkler systems shall be either wet pipe or preaction, > designed and installed in accordance with the applicable > sections of NFPA 13 and the provisions of this chapter. > > If 13 allows it for wet systems, so does 409 as stated above, so > since 13 > allows the 12'6" in 25' bays so does 409. > > I believe your reading the 12' max spacing from the foam or deluge > sections, > not the closed head water sprinkler system section. > > Thom McMahon, SET > Firetech, Inc. > 2560 Copper Ridge Dr > P.O. Box 882136 > Steamboat Springs, CO 80488 > Tel: 970-879-7952 > Fax: 970-879-7926 > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Ray > Vance > Sent: Thursday, February 25, 2010 12:22 PM > To: [email protected] > Subject: Aircraft Hangar Question of the Day! > > To my esteemed colleagues: > > I have an aircraft hangar I am looking at and would like > clarification on > sprinkler / branchline spacing. I know what I think ;-) > However, I would like the combined knowledge of all of you as to the > actual > requirements of the NFPA standards. > > The hangar is a 32,000 suare feet Group-I hanger with a door opening > to > accomodate a 36 ft tail height. > The chosen fire protection scheme is Option-3, a closed-head wet-pipe > sprinkler system at .17 gpm / 15,000 square feet and a low-level hi- > ex foam > system. > The building is a metal-purlin building with 25 ft bay spacing. > > NFPA-409 requires a maximum 130 sf sprinkler spacing with a maximum > distance > of 12 feet between the sprinklers or the branch-lines. > NFPA-409 does not reference NFPA-13 for sprinkler or branch-line > spacing. > > Question: > > In a building with 25 ft bays would one be allowed to space the > branch-lines > at 12'-6" as indicated in NFPA-13 for storage bays at 25 feet > spacing in > lieu of the 12 feet as indicated in NFPA-409? > > Thanks, > > Ray Vance - SET > Chief Sales Designer > Wayne Automatic Fire Sprinklers, Inc. > www.waynefire.com<http://www.waynefire.com> > 407-877-5563 office > 321-436-2184 mobile > > _______________________________________________ > 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) > > _______________________________________________ > 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)
