Russell, My understanding is we do not have to figure the loss for the fitting the sprinkler is in because when the K Factor was being established it was in a fitting. NFPA 13 (2016) 23.4.4.8.1 (9) confirms that. But it's a good question because we're supposed to use a manufacturer's published loss if they have one. So would it make sense to, if the published loss is greater, subtract the loss shown in 13, and include that difference?
Brad On Oct 4, 2016 3:08 AM, "Russell & Carol Gregory" <[email protected]> wrote: > When calculating a Range Pipe with welded threaded outlets for sprinklers > it is not necessary to include a loss for the water leaving the range pipe > and entering the sprinkler. The total pressure is assumed to apply to the > sprinkler orfice. > > This means that a 80nb pipe with a 25nb outlet and a k36 sprinkler does > not have an additional loss added for the outlet fitting. > > > > If I change my design and fabricate the 80nb range pipe with 80 x 25 > Mechanical Tees for the Sprinkler outlet do I have to apply an additional > loss factor for that fitting? The published EQL for Mech tees varies > greatly between brands,( 0.8m up to 2.4m). This means a head pressure of > 345kPa would need around 600kPa in the range if this additional loss is > added. > > > > I would appreciate the Forum members advise as to what is the standard > practice in the USA, and whether the additional loss is to be included. > > > > Russell Gregory > > Christchurch > > New Zealand > > > > e-mail [email protected] > > > > _______________________________________________ > 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
