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?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
