4" with C=.72 would work Steve, thanks. I thought the big one was 5 1/4"!
I should try to get out more. Brad . On Feb 24, 2017 10:03 AM, "Steve Leyton" <[email protected]> wrote: > Uhhhhhh … maybe it’s a 4” port? > > > > *From:* Sprinklerforum [mailto:[email protected]. > org] *On Behalf Of *Brad Casterline > *Sent:* Friday, February 24, 2017 4:19 AM > *To:* [email protected] > *Subject:* Re: Do Hydrant Butts have a K Factor? > > > > Just one more thing if the Forum will suffer me-- > A while back I was looking at some flow test data and I thought I had the > size and type of butt figured out to be 2.5" C=.9. > > Static= 112 psi > Residual= 98 psi > Pitot= 40 psi > 4320 gpm @ 20 psi > > Something was bothering me because if it was a 2.5" C=.9 I get 2912 gpm @ > 20 psi. > > I Googled 'California hydrant butts' thinking they might have some weird > size butts and after I got past a hot chick exercising outside didn't see > anything unusual. > > So it's still a puzzle for me and I don't want to bother the poster of > that data, hoping someone here has a simple explanation. > > Thanks, > > Brad > . > > On Feb 23, 2017 3:09 PM, "Brad Casterline" <[email protected]> wrote: > > Good advice on using the NFPA formulas Travis, thanks, and when I am 'on > the clock' I do. > Thanks John. I didn't care during my first twenty years. But I always had > an uneasy feeling when "everything I know about hydraulics I learned from > the rules in NFPA 13". Unlike you, I was an English Major when I dropped > out of college. Now this question is merely an after-hour curiosity, for > entertainment purposes only if you will. > That FM 2 1/2" K looks like C=.8 Allan, thanks. > > Brad > > On Feb 22, 2017 11:42 PM, "IPA" <[email protected]> wrote: > > 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 85298 > > 480-505-9271 <(480)%20505-9271> > > fax: 866-430-6107 <(866)%20430-6107> > > email:[email protected] > > > > http://www.mfpdesign.com > > https://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 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 > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler. > org > >
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