George, I will research this and let u know about 3/4 pipe. I do remember hearing that it did not change until one of the original NBFU guys died about 1940. Chicago pipe schedule used 3/4 pipe until about 1950.
I know the old style sprinklers went out the year I was born -- 1952. Dave On Thursday, April 26, 2012, George Church wrote: > That is a relatively recent change in the good old days that I've never > really heard definitive answers on when the 3/4" went away and when > staggered changed. > Before my time, I only go back to the end of 3.5" and 5", scheduled > systems, threaded fittings and 2' away start the grooved couplings, and > water motor gongs. > > I remember thinking I was following a 669 fitter in a parking lot since > his license plate was WMAG 300 > Water Motor Alarm Gong, 300 machine, right? What else could it be? > Uh, Winchester magnum 300 was the rather confused answer I got. > Oh, yeah, I guess it could be that, too. > > Guess its obvious I don't hunt. > > George L. Church, Jr., CET > Rowe Sprinkler Systems, Inc. > PO Box 407, Middleburg, PA 17842 > 877-324-ROWE 570-837-6335 fax > [email protected] <javascript:;> > > > > -----Original Message----- > From: [email protected] <javascript:;> [mailto: > [email protected] <javascript:;>] On Behalf Of > David deVries > Sent: Thursday, April 26, 2012 5:04 PM > To: [email protected] <javascript:;> > Subject: Re: Rounding off {Squaring off?} > > Don't know if there is a connection without researching it, but it seems > that staggered sprinklers went out about the same time as standard spray > sprinklers replaced old style sprinklers and their narrower distribution > pattern. > > Dave > > On Thursday, April 26, 2012, wrote: > > > > > > > In the "old days" heads were staggered to help even out the flow as > > well as hasten the acttivation. > > > > > > > > David Bohannon > > > > > > > > Fire Sprinkler Plan Review City of Atlanta > > > > > > > > Department of Planning and Community Development > > > > > > > > Office of Buildings > > > > > > > > 55 Trinity Avenue > > > > > > > > Suite 3900 > > > > > > > > Atlanta, GA 30303 > > > > > > > > e-mail: [email protected] <javascript:;> <javascript:;> > > > > > > > > phone: 404-330-6193 > > > > > > > > fax: 404-739-4172 > > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > > From: "Mark Sornsin" <[email protected] <javascript:;><javascript:;>> > > To: [email protected] <javascript:;> <javascript:;> > > Sent: Wednesday, April 25, 2012 4:18:18 PM > > Subject: RE: Rounding off {Squaring off?} > > > > I think it ultimately goes to the fact that they needed a simple way > > to space sprinklers and square is much easier to work with than round. > > > > As to the safety factor, Bruce pretty much hit it: it works. What is > > implied is that whatever the safety factor is it must be enough. The > > problem is, if you try to analyze the actual factor of safety you have > > to first ignore several other potential influences on that factor. > > Accuracy of the water supply information; actual pressure at the > > sprinkler; choice in design area (which may be affecting the actual > > pressure on the sprinklers); effect on calculations of including hose > > allowances and/or domestic allowances; effect on calculations of using > > assumed (vs actual) friction coefficients for the pipes; etc. When > > some people make the point that sprinkler calculations have 'so much' > > safety factor built into them they are essentially correct. But why do > > people make those assertions? Usually it is to justify lack of > > conformity to standards; and the problem with going down that road is > > that none of these above influences can be precisely measured in terms > > of additional safety factor they may or may not be providing. True, > > some jurisdictions will waive hose allowances in calculations under > > limited circumstances if it means saving the added cost of a pump > > and/or tank. Certainly the knowledge of the remaining potential > > factors of safety is a reason for doing this (on a limited basis). But > > you don't want to push it any farther than disregarding one fairly > measurable variable because uncertainty raises exponentially with each > added variable. > > > > So the bottom line in my view is that one could certainly do a > > mathematical exercise where they calculate the safety factor of all of > > the overlap in sprinkler sprays; but first they would have to make > > assumptions about those other influences. By the time they are done > > doing that, the exercise is nearly worthless, except as a bit of > > intrigue for those of us in the business. > > > > BTW - you can go to some manufacturer's web sites and view sprinkler > > spray patters. If you look at the Viking M 1/2 in. upright, you'll see > > that at 7psi, the spray from about 8 ft. above the floor reaches just > over 9 ft. > > from the centerline of the sprinkler. In a Light Hazard Occupancy, > > that overlaps the 7'-6" maximum distance, but does not reach the > > maximum diagonal distance of 10.6 ft. At 30 psi, you get closer to the > 10.6 ft. > > Obviously, at smaller spacing, the overlap increases (another variable > > to consider). > > > > Mark A. Sornsin, PE| Fire Protection Engineer Ulteig Engineers, Inc.| > > Fargo, ND [email protected] > > > > > > -----Original Message----- > > From: [email protected] <javascript:;> [mailto: > > [email protected] <javascript:;>] On Behalf Of > Bruce Verhei > > Sent: Tuesday, April 24, 2012 12:51 PM > > To: [email protected] <javascript:;> > > Subject: Re: Rounding off {Squaring off?} > > > > I've read in the past that this fell in the not well understood effect > > category when engineers have desired to model how sprinklers actually > work. > > This seems to be difficult. They say something that ends with but > > sprinklers installed and maintained to standards have a remarkable > > record of controlling fires in buildings. > > > > I want to buy one of the square heads. Are the threads square too? > > > > Bruce > > > > Sent from my Motorola ATRIXT 4G on AT&T > > > > -----Original message----- > > From: Thomas Watt <[email protected] <javascript:;>> > > To: [email protected] <javascript:;> > > Sent: Tue, Apr 24, 2012 13:05:01 GMT+00:00 > > Subject: Rounding off {Squaring off?} > > > > I had a brain-fart and came up with this question for the forum. > > Especially the engineers. Since sprinklers, in general, throw in a > > circular pattern, and we calc the sprinklers as squares, there is > > always overlap so we are by default miscalculating a percentage of the > density. > > Has anyone ever calculated the safety factor effect by ignoring the > > arcs outside the square??? > > > > Thomas > > A+ fitter/Foreman > > No work in Orlando, FL area > > Willing to relocate > > -------------- next part -------------- An HTML attachment was > > scrubbed... > > URL: < > > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attac > > hments/20120424/5639c5b1/attachment.html > > > > > ________________________URL: < > > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attac > > hments/20120426/f2dde620/attachment.html > > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] <javascript:;> <javascript:;> > > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120426/c9ca1cc2/attachment.html > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] <javascript:;> > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > _______________________________________________ > Sprinklerforum mailing list > [email protected] <javascript:;> > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -------------- next part -------------- An HTML attachment was scrubbed... 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