Steve, Thanks, and yes, in order to meet the 240 lb load the braces would need to be spaced at 5' o.c. Adding the longitudinal braces seems to be my best option at this point.
Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steve Leyton Sent: Monday, June 01, 2009 1:59 PM To: [email protected] Subject: RE: Longitudinal Sway Brace on Branch Line I would say, 1) If both sides are in the ZOI, then you have to brace both sides; 2) Yes. 3) NFPA 13 doesn't distinguish between mains and lines - the language says that the distance between the last brace and "end of pipe" shall not exceed 40'. Have you tried crunching down the spacing of the seismic braces on the mains to dilute the load? Steve Leyton Protection Design & Consulting San Diego, CA -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bob Knight Sent: Monday, June 01, 2009 12:53 PM To: [email protected] Subject: Longitudinal Sway Brace on Branch Line I have a situation where there are open web joists (wood t&b cord w/ open metal web). The system is a tree with 4" main and 1-1/2" branch lines. The problem is loading, the manufactures data allows only 240 lbs of force, and when I apply the loading from both sides of the cross main the weight is well over 240. NFPA 13 9.3.5.6.4 dictates that the zones of influence include all the branch and main lines tributary to the brace, but provides for an exception when the branch lines are provided with longitudinal braces. So, my questions are: 1) Is one longitudinal brace per cross main intersection adequate or is it necessary to provide a brace on both sides of the cross main? 2) Is my maximum spacing the same for branch lines as it is for mains, 80'? 3) Do I need to have the brace within 40' of the end of the branch line? Thanks, 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) __________ Information from ESET NOD32 Antivirus, version of virus signature database 4120 (20090601) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 4120 (20090601) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.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) _______________________________________________ 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)
