I believe I saved this info from this very forum but I have noted that FM global used to have k-factors for hydrants. Here are the values: 2 3/8" 134 2 1/2" 149 2 5/8" 164
On Wed, Feb 22, 2017 at 6:48 PM, John Denhardt <[email protected] > wrote: > Travis - well said > > Brad - who really cares if hydrants have a K factor? I know I don't. > > John August Denhardt, P.E. > Strickland Fire Protection > > On Feb 22, 2017, at 8:45 PM, Travis Mack, SET <[email protected]> wrote: > > Or just use the formula in NFPA 291- Standard for Hydrant Marking and flow > tests or something like that... > > Q = 29.83*d^2*Cd*P^0.5 > > d = hydrant outlet diameter in inches > > C = the outlet coefficient (0.7, 0.8 or 0.9) > > P = Pitot pressure that is measured > > Not everything has to be extremely complicated and thought out to the nth > degree. If you are really so inclined, why not spend the next few years > solving for Pi to the 1,000,000th point. And guess what...... if you > assign K to be 29.83*d^2*Cd........ you get 168 for your example. > Wow...sometimes the simplest methods are the best. > > There is a true phenomenon that causes many people problems - *paralysis > through analysis*. > > > Travis Mack, SET > MFP Design, LLC > 2508 E Lodgepole Drive > Gilbert, AZ 85298480-505-9271 <(480)%20505-9271> > fax: 866-430-6107 <(866)%20430-6107>email:[email protected] > http://www.mfpdesign.comhttps://www.facebook.com/pages/MFP-Design-LLC/92218417692 > Send large files to us via: https://www.hightail.com/u/MFPDesign > LinkedIn: https://www.linkedin.com/in/travismack > > On 2/22/2017 5:58 PM, Brad Casterline wrote: > > Say it's a 2.5" C=.9. > > I've tried to work this out a couple different ways: > 1) a kind of long drawn out way, call it 'brad's way', and I get ~168. > 2) a way i call the 'Bill Brooks back of napkin' way based on a few words > he posted here a few years ago-- lightening fast, and i'll be damned if i > dont get the same ~168! Basically, since K is the square feet area of the > orifice he says 5*5*5.6=140, times (.9/.75) = 168. > Anyway, if a hydrant butt has a K we could pretty quickly get the Q after > the pitot'd P with Q=K*SQRT(P). > > thanks, > > Brad > . > > > _______________________________________________ > Sprinklerforum mailing > [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 > >
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