The annex shows the branch lines fed by the cross main from two directions, the sprinkler can still only receive water from one direction from the branch line... that is the distinction in the definition.
The above is my opinion and has not been processed as a formal interpretation in accordance with the NFPA Regulations Governing Committee Projects. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. AFSA cannot provide design or consulting engineering services, and this opinion should therefore not be considered, nor relied upon, as such. Kevin Hall, M.Eng., P.E., ET, CWBSP, PMSFPE Coordinator, Engineering and Technical Services American Fire Sprinkler Association [email protected] 214-349-5971 On Wed, Oct 27, 2021 at 12:05 PM J H via Sprinklerforum < [email protected]> wrote: > I have a problem with the simplified definition floated out here that a > grid system is one that feeds a sprinkler from two directions because of > the illustration of a looped system in the annex of '13 which shows > sprinklers attached to the end portion of the loop resulting in those > sprinklers receiving water from two directions. Technically the only cross > main is the center piping - everything else are looped branchlines. I would > be prepared for kickback from a knowledgeable AHJ. I would personally avoid > a design like this if at all possible to avoid the headache of hashing it > out w/ an AHJ. But if it's the difference between a system like this and a > fire pump it might be worth the fight. > > JH > > On Wed, Oct 27, 2021 at 6:04 AM Sean Conlin via Sprinklerforum < > [email protected]> wrote: > > > If you were to put caps on the left and right lines going north and > south, > > it resembles a compound gridded system and a sprinkler can receive water > > from both sides. > > > > The east and west lines are essentially the mains and so is the 4" in the > > middle. > > > > Yes is has a looped piping arrangement and is symmetrical but it is a > > gridded system by NFPA-13 definition. If you were to not tie the lines > > together, it would be a loop. > > > > Regards, > > > > Sean W. Conlin > > E:[email protected] > > > > This message, including any attachments is considered confidential and > for > > use only by the intended recipient(s). > > Any other distribution, copying or disclosure is strictly prohibited. > > Please delete this communication and notify > > Demand Sprinkler Design Inc. if you are not the intended recipient or > have > > received this message in error. Demand > > Sprinkler Design Inc. accepts no responsibility or liability for any loss > > or damage from use, including damage from viruses. > > > > -----Original Message----- > > From: Ed Kramer <[email protected]> > > Sent: October 26, 2021 1:31 PM > > To: [email protected] > > Subject: Gridded dry system > > > > Is this sprinkler system a gridded system? I've avoided this type of > > design in the past for dry systems because it 'kinda' a grid, but not > > really. Now I'm questioning my questioning. What are your thoughts? > > > > > > > > Reference NFPA 13 (2019) sections 8.2.3.10 and 3.3.206.5. > > > > > > > > https://www.dropbox.com/s/u2hw3cbvlga4fcq/Dry%20Attic%20System.pdf?dl=0 > > > > > > > > > > > > Ed Kramer > > > > > > > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
