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)
