Thanks Cecil. I have not yet received your first post. My email server has been redirecting these forum posts since the email problem a few weeks ago. Time to check the spam folder. Hopefully there are no work emails hiding in there!
Jack Fairchild -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Sprinkler Academy - C Bilbo Sent: Monday, May 06, 2013 4:08 PM To: [email protected] Subject: RE: K-Factor Jack, As I said in my earlier post, "Dude, I teach my students that ....it simply defines "the hole"." It is nice to think that NFPA 13 would also refer to it in nearly the same terms. Therefore, I would point you to the new item in Table 1.6.2 of the 2013 edition (the previous 1.7.2): "K K-factor" I'll also refer you to section 3.6.1 where it states that a sprinkler is defined by many things including its K-factor. And it tells us to see chapter 6. Wherein, we are told that sprinkler identification shall include the "K-factor (orifice size)". We are also refered by other Chapter 6 language to see Table 6.2.3.1. In this table, the K-factor is then simplified as "Nominal K-factor [gpm/(psi)^2]" And make no mistake, this is from a simplification of Bernoulli's work, Torricelli only made Bernoulli's 1768 work possible.... Torricelli's concepts were too narrow for us to use.... So if you are going to draw on Torricelli, you may as well include Pascal... and none of the math can be applied because neither you, nor I, nor anyone else has enough information (save the savvy sprinkler manufacturer) to actually perform the correct math for a sprinkler application. (Pay no attention to the man behind the curtain...) So I will say again, for our purposes it is "The Size of the Hole". Now, does anyone have a rock I can crawl under..... hmmm??? It should be recognized that the above is my opinion as a member of the NFPA 13 Committee, and has not been processed as a formal interpretation in accordance with the NFPA Regulations Governing Committee Projects and should therefore not be considered, nor relied upon, as the official position of the the NFPA, nor any of their technical committees. Sincerely, Cecil Bilbo Academy of Fire Sprinkler Technology Champaign, IL 217.607.0325 www.sprinkleracademy.com [email protected] OUR STUDENTS SAVE LIVES!! > From: [email protected] > To: [email protected] > Date: Mon, 6 May 2013 11:11:54 -0400 > Subject: RE: K-Factor > > Thank you all for the responses. I knew what it represented, but was > surprised it's not defined in chapter 1 or 2. Looks like it should be > shown in table 1.7.2. (NFPA 13, 2007) > > Jack Fairchild > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > Brad Casterline > Sent: Monday, May 06, 2013 7:41 AM > To: [email protected] > Subject: RE: K-Factor > > Uhhh... thanks DJJ8389? Me? If someone whom has spent years trying to > wring the magic out of NFPA 13 Hydraulic Calculations is a genius, > then so be it > :) > > I wanted to add something important about K that struck me just recently: in > looking at Q, K, and P, and knowing g = 32.2 ft/sec2, K is seen to be unique > in that it is the only 'timeless' quantity of the bunch! > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Sunday, May 05, 2013 7:19 PM > To: [email protected] > Subject: Re: K-Factor > > Wow. You are a genius. > > > In a message dated 5/5/2013 12:46:06 P.M. Eastern Daylight Time, > [email protected] writes: > > cubic feet per second, divided by square feet, equals feet per second. > Q is (ft x ft x ft) / second. > K is ft x ft. > P is (ft/sec x ft/sec, divided by 64.4)*, times .433. > This is IDEAL. Play pipes are ~98% ideal. Some hydrant butts are ~80% ideal. > > * h=(v2/2g) is as per Evangelista Torricelli, years before Bernoulli. > Newton > used the experimental results of this, later called 'The Law of Falling > Bodies', as one of the verifications of his Gravitational Constant. So if > someone asked me "What is K-Factor?", I would say "It is the constant area > acted upon by constant gravity around which Flow and Pressure vary". > > -----Original Message----- > From: Ron Greenman [mailto:[email protected]] > Sent: Friday, May 03, 2013 6:13 PM > To: [email protected] > Subject: Re: K-Factor > > I would define it as a number representing a fixed and repeating set > of circumstances in a closed system (numerically closed) that would > otherwise be variable. For instance the K in the formulae Q=KP^0.5 > represents the > 29.83cd^2 when those factors are consistent. Hence with a sprinkler head, > which has a known co-efficient and diameter, you can reduce those factors to > a single number. That would apply to a branchline also wherein you can reduce > the entire Q-P relationship to one big hole. You can use this again and again > as long as the pieces that made up the original batch of calculations are > exactly repeated. Saves you from having to calculate the same relationship > over and over. calculation shorthand. I was in the middle of the last > sentence an hour and a half ago, before Vince and Cecil responded. But here's > my explanation of the same thing with different words. > > > On Fri, May 3, 2013 at 1:36 PM, Fairchild, Jack > <[email protected] > > wrote: > > > Here's a Friday question that was asked of me: What's a K-Factor? > > > > The Brock Hydraulics book states it is the discharge coefficient, > > but I can't find it in NFPA 13. Am I missing it? > > > > Jack Fairchild > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > > > > > > -- > Ron Greenman > 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-firesprinkl > er.org > > _______________________________________________ > 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 > > _______________________________________________ > 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 _______________________________________________ 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
