Here's a variation on a theme question. 22.4.1.2 (2007) requires that all piping in a hydraulically calculated system be no less than 1". Does this mean if you take an older pipe-schedule system and revamp it, or do, basically, anything that would require hydraulic calculations (add a fire pump, change occupancy, etc), would you be required to replace all of the existing 3/4" pipe with 1" pipe?
Benjamin Young On Mon, Jun 25, 2012 at 6:32 AM, Johnson, Duane (NIH/OD/ORS) [C] < [email protected]> wrote: > 8.15.19.4.1 When pipe schedule systems are revamped, a nipple not > exceeding 4 in. (100 mm) in length shall be permitted to be installed in > the branch line fitting. > > 8.15.19.4.2 All piping other than the nipple permitted in 8.15.19.4.1 > and 8.15.19.4.3 shall be a minimum of 1 in. (25 mm) in diameter in > accordance with Figure 8.15.19.4.2. > > 8.15.19.4.3 When it is necessary to pipe two new ceiling sprinklers from > an existing outlet in an overhead system, the use of a nipple not exceeding > 4 in. (100 mm) in length and of the same pipe thread size as the existing > outlet shall be permitted, provided that a hydraulic calculation verifies > that the design flow rate will be achieved in accordance with Figure > 8.15.19.4.3. > > 8.15.19.4.4 The use of pipe nipples less than 1 in. (25 mm) in diameter > shall not be permitted where seismic design is required on the system. > > Duane Johnson, PE > Program Manager > Division of the Fire Marshal (Support Contractor) > Office of Research Services > National Institutes of Health > 301-496-0487 > > "Protecting Science - One Sprinkler at a Time" > > > -----Original Message----- > From: Jarron Gass [mailto:[email protected]] > Sent: Friday, June 22, 2012 4:55 PM > To: [email protected] > Subject: 3/4" Pipe and Sprigs > > > > Folks, > > > > I am working on an older building, pipe scheduled system with ¾” pipe at > the end of some lines as well as ¾” sprigs in some areas. As best we can > tell, the bulk of the system is from about 1930. In NFPA13, 2011 edition > it says the following: > > > > 22.4.1.2 Pipe sizes shall be no less than 1 in. (25 mm) nominal > > for ferrous piping and 3⁄4 in. (20 mm) nominal for copper > > tubing or nonmetallic piping listed for fire sprinkler service. > > > > This is referencing hydraulic calculations, but I seem to recall that > there was a requirement somewhere in the standard to remove any ¾” piping > and replace with 1”. If so, can anyone point me to the proper section and > also, would that include the sprigs? It seems a little frivolous to remove > the existing 1’-0” long sprigs and install an extra heavy close nipple with > a ¾” x 1” reducing coupling, a short piece of 1” pipe and another reducing > coupling. > > > > I appreciate any input. > > > > Thanks, > > > > Jarron > > > > > > > > Jarron J. Gass - J. & J. Fire Protection Co., Inc. > > 101 Powell Rd., Butler, PA 16002, (724) 586-6111, fax (724) 586-5151 > > emergency (724) 898-2481, <mailto:[email protected]> > [email protected], <http://www.jandjfire.com> www.jandjfire.com > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120622/28498e45/attachment.html > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: image001.gif > Type: image/gif > Size: 862 bytes > Desc: not available > URL: < > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120622/28498e45/attachment.gif > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120625/cf68c622/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
