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. 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