The pipe condition where there is flowing water will be reflected in the flow test. Which is why you always want to have water flowing past your present or future connection point, whenever possible. You could always do a gradient (multiple gauge locations and a single flow point) to determine existing C factors but that only works on dead end mains.
Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT www.fpdc.com 860-535-2080 (ofc) > On Jun 19, 2014, at 11:12 AM, "Mark A. Sornsin, P.E." <[email protected]> > wrote: > > ..and it's also a bigger problem if you're not dealing with 8" DIP, but 50 yr > old cast iron pipe. I have seen that differentiation blown off many times, > but the repercussions CAN be significant. What is the C factor on 50 yr. old > cast iron? If you can't determine it empirically, then FM may tell you 75 to > as low as 40. Which equates to about 3.5 psi to 11 psi, respectively, at 400 > gpm (& 1,000 ft.). So which coefficient would you use if FM was not on the > job? What would "code" require? > > Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer > | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | > http://www.kfiengineers.com > > -----Original Message----- > From: Sprinklerforum [mailto:[email protected]] > On Behalf Of Scott A Futrell > Sent: Thursday, June 19, 2014 9:21 AM > To: [email protected] > Subject: RE: Location of Flow Test in Calc's > > Totally agree, however if the concept isn't understood it morphs to the email > that started this thread. 400 gpm through old 4" or 6" is a bigger problem. > > The right way is to calculate to the flow, get the information to do it > right. If it is a single-feed loop and you are on the remote end of that > loop from the supply and the test, you need to account for the loss. > > Scott > > (763) 425-1001x12 Office > (612) 759-5556 Cell > > -----Original Message----- > From: Sprinklerforum [mailto:[email protected]] > On Behalf Of IPA > Sent: Thursday, June 19, 2014 9:08 AM > To: [email protected] > Subject: Re: Location of Flow Test in Calc's > > In light & ordinary hazards it's usually not a big deal as long as you've > accounted for elevation differences. 400 gpm flowing through a thousand feet > of 8" DIP equates to a little over 1 psi friction loss. > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please visit http://www.symanteccloud.com > ______________________________________________________________________ > _______________________________________________ > 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
