IMHO, defining a grid as any system that can supply a sprinkler from more than one direction is a poor threshold. Just because you install sprinklers on a looped main or line, does not magically turn it into a gridded system. The location of the sprinklers should have nothing to do with it.
May I suggest the following definition of gridded piping: "piping installed such that any loop in the system has more than one connection capable of providing water to the loop from the same supply; a loopty loop." Maybe leave the last part out. Up to you. -Skyler On Wed, Oct 27, 2021, 12:17 PM Chad Mitchell via Sprinklerforum < [email protected]> wrote: > Here is an Informal Interpretation of a similar layout from November 13, > 2009. > > https://www.dropbox.com/sh/8e4v0xvfri07c5i/AADbhtdz25iS_1Qkdbnh1lWqa?dl=0 > > Regards, > > Chad Mitchell > Mid Atlantic Fire Protection, Inc. > > -----Original Message----- > From: Sprinklerforum <[email protected]> On > Behalf Of J H via Sprinklerforum > Sent: Wednesday, October 27, 2021 1:03 PM > Cc: J H <[email protected]>; > [email protected] > Subject: Re: Gridded dry system > > So, on any looped system, if you add sprinklers to the looped main (adding > flow from more than two directions) does that now constitute a grid? I see > both viewpoints but am posing as devil's advocate. As I said I would steer > clear from the original scenario unless necessity dictated otherwise. > > JH > > On Wed, Oct 27, 2021 at 9:58 AM J H <[email protected]> wrote: > > > I would call it a Tree/Loop hybrid. :-P > > > > The branchlines are not connecting two parallel cross mains per the > > definition of a grid. > > JH > > > > > > On Wed, Oct 27, 2021 at 9:50 AM Kevin Hall <[email protected]> > > wrote: > > > >> 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?d > >>> l=0 > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > Ed Kramer > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > _______________________________________________ > >>> >>> > > > Sprinklerforum mailing list > >>> >>> > > > [email protected] > >>> >>> > > > > >>> >>> > > > > >>> >>> > > > >>> >>> > > >>> >>> > >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprin > >>> kler.org > >>> >>> > > > > >>> >>> > > _______________________________________________ > >>> >>> > > Sprinklerforum mailing list > >>> >>> > > [email protected] > >>> >>> > > > >>> >>> > > > >>> >>> > > >>> >>> > >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprin > >>> kler.org > >>> >>> > > > >>> >>> > _______________________________________________ > >>> >>> > Sprinklerforum mailing list > >>> >>> > [email protected] > >>> >>> > > >>> >>> > > >>> >>> > >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprin > >>> kler.org > >>> >>> > > >>> >>> _______________________________________________ > >>> >>> Sprinklerforum mailing list > >>> >>> [email protected] > >>> >>> > >>> >>> > >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprin > >>> kler.org > >>> >>> > >>> >> > >>> _______________________________________________ > >>> Sprinklerforum mailing list > >>> [email protected] > >>> > >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprin > >>> kler.org > >>> > >> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > This email and any files transmitted with it are confidential and intended > solely for the use of the individual or entity to whom they are addressed. > If you have received this email in error please notify the system manager. > This message contains confidential information and is intended only for the > individual named. 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