Thanks Matt and Ron. I appreciate ALL feedback. I like posting numbers because there is no opinion, personal feelings, hearsay, etc. I know a ton about D-W and H-W, and I do not need to repeat the Velocity of Efflux experiments of the early 1600's to know I am correct about K-Factors. Would it be too much to ask of you to simply work a few of the numbers that back up the concepts I post, BEFORE I get your Criticisms and Opinions? Either that or YOU show ME how it is done- adjusting K-Factors I mean, from NFPA 13 referenced earlier?
-----Original Message----- From: Ron Greenman [mailto:[email protected]] Sent: Tuesday, June 11, 2013 2:03 PM To: [email protected] Subject: Re: adjusting the K-Factor with our bare hands can I say strongly enough how much I agree with what Matt said? can I say it again? And third time being the charm, I agree with what Matt said--a lot--and with George's earlier comments. On Tue, Jun 11, 2013 at 11:40 AM, Matt Grise <[email protected]> wrote: > I would strongly caution against using this method for estimate > calculations. (Without doing extensive testing to verify that it is > accurate) > > The D-W and H-W calculation methods are simply approximations of how > fluids interact with themselves and the pipe they are in. The H-W equation > and the K-factor concept are two VERY specialized cases that are intended > only to describe warm water in pipes coming out of a smooth hole. > > The k-factor only relates the ease with which water can escape a > sprinkler. If you plug in a modified k-factor, you are still using H-W to > describe how the fluid is moving through the pipes. The reason that you > have to switch to the D-W equation is because H-W will give you the wrong > answer. If you use a modified K factor with H-W (instead of D-W) the most > likely outcome is a wrong answer - although maybe not the same wrong answer > as before. > > Matt Grisé PE*, LEED AP, NICET II > Sales Engineer > Alliance Fire Protection > 130 w 9th Ave. > North Kansas City, MO 64116 > > *Licensed in KS & MO > > 913.888.0647 ph > 913.888.0618 f > 913.927.0222 cell > www. AFPsprink.com > > > > On Jun 11, 2013, at 7:52 AM, "Brad Casterline" <[email protected]> > wrote: > > > From NFPA 13-2007, 22.4.4.5.1, we are required to, among other things, > > adjust the K-Factor. > > > > Using the Hazen-Williams friction formula, 62.4 lb/ft3 / 144 in2 = .433 > > lb/in2/ft(h). > > > > If we have an AF solution at 65.5 lb/ft3, / 144 = .455 lb/in2/ft(h). > > > > If K=5.6, and we assume P=7 PSI.: > > > > 7/.433=16.166 ft(h). 7/.455=15.385 ft(h).* > > > > 15.385/16.166=.952. sqrt(.952)=.976, x 5.6 = 5.46. > > > > There is a chart in 13 showing a 50% glycerin solution at about -10F > > weighing about 15% more than 100% water: 62.4 x 1.15 = 71.76. > > 71.76/144=.498. 7/.498=14.056 ft(h). 14.056/16.166=.869. > sqrt(.869)=.932, x > > 5.6 = 5.22. > > > > If I had to fab the pipe today and formalize the submittal tomorrow > (after > > googling centipoises for several hours) I would calc it like it was 'all > > wet', using K=5.22. > > > > * converting PSI to feet of head(h) it is seen that the denser the > solution, > > the 'shorter' it is. Since v=sqrt(2gh), the shorter it is the slower it > is. > > Making the adjustment based on "h", we have to take the square root of > the > > ratio, i.e., (K=Q/sqrtP). If adjusted based on velocity we would use the > > ratio itself (square feet=cubic feet per second divided by feet per > second): > > sqrt(2*32.2*16.166)=32.266 ft/sec. > > > > sqrt(2*32.2*15.385)=31.477 ft/sec. > > > > 31.477/32.266=.976. > > > > > > > > The above is simply the type of thing I enjoy doing and like to share, > > hoping it will cause no harm, to be taken or left as one sees fit. > > > > > > > > thanks, > > > > > > > > Brad Casterline, NICET IV > > > > Fire Protection Division > > > > > > > > FSC, Inc. > > > > P: 913-722-3473 > > > > [email protected] > > > > www.fsc-inc.com > > > > > > > > Engineering Solutions for the Built Environment > > > > > > > > _______________________________________________ > > 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 > -- Ron Greenman (???????? ???? ????? 6 ??????) Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ 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
