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-firesprinkler.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-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
