If the pipe marked in red is removed and capped off, it eliminates any split flows/transfer lines on the branch lines. So with the red pipe removed I would define it as a tree. With the red pipe installed, I would define it as a grid.
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 12:47 PM J H via Sprinklerforum < [email protected]> wrote: > So, for discussions sake take a look at the image link - what would you all > call this system? I have my opinion but I don't see how it's much different > than Ed's original drawing: > https://ibb.co/xSW04dj > > On Wed, Oct 27, 2021 at 9:46 AM J H <[email protected]> wrote: > > > So, for discussions sake take a look at the image link - what would you > > all call this system? I have my opinion but I don't see how it's much > > different than Ed's original drawing: > > https://ibb.co/xSW04dj > > > > On Wed, Oct 27, 2021 at 9:40 AM Kevin Hall <[email protected]> > > wrote: > > > >> Yes, I see that now... looks like I have another PI to add to the NFPA > 13 > >> list. Look for that line of sprinklers to be removed in the 2025 edition > >> haha. > >> > >> 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 12:19 PM J H via Sprinklerforum < > >> [email protected]> wrote: > >> > >>> Kevin, > >>> That's true for most of the sprinklers in the diagram but look at > figure > >>> A.3.3.206.6 (2019) - the farthest loop from the supply has sprinklers > on > >>> it > >>> and it's connecting both loops - those sprinklers are receiving water > >>> from > >>> two mains. Likewise, per the definition of a main the only main in Ed's > >>> example is the center line. Everything else are looped branchlines per > >>> the > >>> definitions. > >>> > >>> JH > >>> > >>> > >>> On Wed, Oct 27, 2021 at 9:09 AM Kevin Hall via Sprinklerforum < > >>> [email protected]> wrote: > >>> > >>> > 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 > >>> > > >>> _______________________________________________ > >>> 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
