Rahe, I don't have my archival copies of 13 handy but I believe your statement is only half right. Your reference is correct for your second paragraph. The allowance for the 1/2 nipple not to exceed 4" in length is elsewhere and used to have a drawing showing the arrangement of a 1/2" Tee outlet with a 1/2" nipple transitioning to a 1/2" x 1" Ell, a 1" short nipple, 1" Ell and finally the drop. This arrangement has never been acceptable in a Seismic Zone.
On Fri, Mar 26, 2010 at 5:25 PM, <[email protected]> wrote: > Here is one that relies on an interpretation of the code from its literal > verbiage. NFPA 13: 8.15.19.5 states "When hydraulically designed systems > are revamped, > any existing bushing shall be removed and a nipple not exceeding 4 in. (100 > mm) in length shall be permitted to be installed in the branch line > fitting." This has historically been taken to mean that a 4 inch by 1/2 > inch nipple can be installed in an existing 1 X ! X 1/2 tee to provide an > armover for a pendent sprinkler to a ceiling below. > > However, this is not what the code states. NFPA 13 is relating to a > bushing that was installed in an unfinished space. In fact, it does not > state what size nipple is acceptable except that it cannot be less than 1 > inch if it is in an earthquake zone. As I read it, you cannot just remove > an upright sprinkler and install a 1/2 inch nipple connected to a 1/2 to 1 > inch increaser and drop it to the ceiling below. What is the consensus > and/or did the standard change sometime ago? > > Thank You > > Rahe Loftin, P.E. > Region 7 - GSA > Office - 817-978-7299 > Fax - 817-978-8644 > Cell - 817-371-3102 > > _______________________________________________ > 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) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC _______________________________________________ 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)
