Thanks Sean. As to stems at 7-10, take a look at the full scale (though limited) cloud ceiling studies that Research Foundation did, where-by they found that, the higher the ceiling, the greater the gap between clouds could be- - - it's the same kind of numbers thing, activation-wise. On Apr 28, 2016 5:41 PM, <[email protected]> wrote:
> Ron, > > Thank you for the input. That's one of the things that drives me crazy. > I'm a numbers person and like to know the supporting information. My jaw > hit the floor when I found out the 3x rule was made up because it had to be > something...and the 4x rule for EC heads was chosen because it is larger > than 3. Come on guys! > > Brad, > > For your puzzle, I think it rhymes with Whoosh > > Thanks, > Sean VG > > > > > > -----Original Message----- > From: Sprinklerforum [mailto: > [email protected]] On Behalf Of Brad > Casterline > Sent: Thursday, April 28, 2016 3:37 PM > To: [email protected] > Subject: Re: NFPA 13 (2013) 8.6.4.1.2(5) - why the 3ft minimum? > > How about stems at 7-10 Ron? > > p.s. I'm working on an X-word puzzle... 6 letters starts with d ends with > e... a little help? > p.s.s. you were right a couple years ago when you told me if I'm looking > for a little love I might be looking in the wrong place. > I wish I was Larry, or Steve L right about now. > On Apr 28, 2016 5:14 PM, "rongreenman ." <[email protected]> wrote: > > > I hate to state the obvious, nor sound like a d....e, but it's because > > it os the rule. It's the same if I have a duct that is 48" wide I need > > to place sprinklers under the duct but i can have multiple ducts 47" > > wide with a gap 1" wide between them, and I can have then all across > > the room and don't have to sprinkler under them. So at some point you > > have to look at common practice and you'd never see my scenario. What > > about yours? Do you regularly run into 2' 11" and 3' 1" stems? > > > > On Thu, Apr 28, 2016 at 3:02 PM, Larry Keeping <[email protected]> > > wrote: > > > > > It may be of help if you reference the 2016 edition of NFPA 13. > > > > > > There, in Section 8.6.4.1.2(5) the 3 ft limit has been deleted. > > > > > > The Committee Statement for that revision was that concrete tees are > > > capable of withstanding the heat long enough for sprinklers to > > > activate even when the tees are closer than 3 feet on centers. > > > > > > Larry Keeping > > > > > > -----Original Message----- > > > From: Sprinklerforum [mailto: > > > [email protected]] On Behalf Of > > > [email protected] > > > Sent: April-28-16 5:35 PM > > > To: [email protected] > > > Subject: NFPA 13 (2013) 8.6.4.1.2(5) - why the 3ft minimum? > > > > > > Forum, > > > > > > We have concrete tee construction. Bottom of stems measured from > > > the ceiling is 26" down. Centerline of stems are spaced apart in an > > > every other fashion of 7', 2'8", 7', 2'8", etc. Ideally we would > > > like to use NFPA 13 (2013) 8.6.4.1.2(5) to protect the area so we > > > don't have to add additional sprinklers/piping. However it states > > > this is only applicable for 3ft to 7.5ft stem spacing. Can someone > > > tell me the purpose behind > > the > > > 3ft minimum threshold? Even though we have some 2'8" sections, do > > > you believe the intent of this code was for my situation? Or do you > > > believe the intent is for concrete tee construction where every stem > > > is 3ft or less? I can see people interpreting this passage either > > > way as all stems are spaced away from another stem more than 3ft, > > > yet all stems are spaced away from another stem less than 3ft. > > > > > > To me, it seems ridiculous that I can have stems with any depth > > > (let's > > say > > > 10ft) and spaced 3'1" apart and the deflector can be located 1" > > > below > > the > > > bottom of the stem (10'1") and branchlines can be spaced 15ft apart. > > > Yet if the same depth stems are spaced 2'11" apart the deflector > > > can't be > > lower > > > than 22" below the ceiling and because they are now obstructed, they > > > have to be in every pocket. > > > > > > I appreciate anyone's opinion on my situation and/or > > > knowledge/history of this codes development. > > > > > > Note: As I allude to, I know there are other ways to design this > > > system utilizing 22" and beam rule. I am more looking for the > > > "Why's" or the > > "You > > > missed this blurb" that agrees with your stance . > > > > > > Thanks, > > > Sean VG > > > > > > > > > > > > > > > > > > _______________________________________________ > > > Sprinklerforum mailing list > > > [email protected] > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > > er.org > > > _______________________________________________ > > > Sprinklerforum mailing list > > > [email protected] > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > > er.org > > > > > > > > > > > -- > > Ron Greenman > > > > 4110 Olson Dr., NW > > Gig Harbor, WA 98335 > > > > [email protected] > > > > 253.576.9700 > > > > A problem well stated is a problem half solved. -Charles F. Kettering, > > inventor and engineer (1876-1958) > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > > er.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
