Oops, forgot the pattern part (thanks Bruce), but the argument is the same. The head is tested/listed at not less than psi. Rule 1 then is 7 psi or more, if less than 7 psi raise the starting pressure to 7 psi, that's it, don't worry, carry on, complete the design, get it out the door, and approved, build-it, get it signed off, collect the money, move on.
On Sun, Jun 3, 2012 at 1:36 PM, Bruce Verhei <bver...@comcast.net> wrote: > Would the heads make an effective pattern below 7psi, and more important, > is the answer known, and not guessed at? > > Bruce > > Sent from my Motorola ATRIX™ 4G on AT&T > > -----Original message----- > From: bcasterl...@fsc-inc.com > To: sprinklerforum@firesprinkler.org > Sent: Sun, Jun 3, 2012 20:31:30 GMT+00:00 > Subject: minimum 7 PSI end head logic, check please! > > Fact: a minimum pressure is required to 'push the stopper out of the > orifice' once the 'link has broken'. This means the column of water above > the head has to be at least 16 feet tall. (i wonder if this is enough for > the 'bigger stoppers' of today, but I'll trust the manufacturers). An > overall statement could be made "Sprinklers do not work where the static is > less than 7 PSI". > Question: Why should we calculate the minimum required flow rate based on > anything other than density times head area, since at that point the > stopper has already been pushed out? > If in doubt about the Pt available to a non-flowing head when others are > flowing, couldn't we use a flow test graph to find GPM at 7 PSI, and make > sure we are flowing less than that? > > _______________________________________________ > Sprinklerforum mailing list > Sprinklerforum@firesprinkler.org > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120603/c7182724/attachment.html > > > _______________________________________________ > Sprinklerforum mailing list > Sprinklerforum@firesprinkler.org > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 rgreen...@bates.ctc.edu 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) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120603/47ad132e/attachment.html> _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
