No, see below. This is because you stated it is a 'pipe schedule system'. If this were a new "hydraulically calculated" system, I would say all piping has to be 1" minimum. This is based on:
1. The reference you provided, 2. 8.15.19.1 In new installations expected to supply sprinklers below a ceiling, minimum 1 in. (25 mm) outlets shall be provided. 3. Section 8.15.19.5. Revamping of Hydraulic Design Systems. 4. A.22.4.1 When additional sprinkler piping is added to an existing system, the existing piping does not have to be increased in size to compensate for the additional sprinklers, provided the new work is calculated and the calculations include that portion of the existing system that can be required to carry water to the new work. It is not necessary to restrict the water velocity when determining friction losses using the Hazen–Williams formula. The commentary has a nice write up on this section. The 3/4" restriction started in 1940 and was primarily implemented to reduce clogging of pipes. All from the 2007 & 2010 edition...sorry Ron, I know better. What confuses me is why does the following paragraph exist if 1" pipe is the minimum size for hydraulic systems: 8.15.19.4.5 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: Ben Young [mailto:[email protected]] Sent: Monday, June 25, 2012 12:34 PM To: [email protected] Subject: Re: 3/4" Pipe and Sprigs 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... 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