In pipe schedule 3.5 was cheaper than 4 (duh...) when it was in common use just as 5 trumped 6. As we evolved and the few places where 3.5 and 5 we used were supplanted by 4 & 6 (not much difference in schedule 10) the two sizes just faded away: less different parts to stock, less different types of material to handle, no appreciable cost benefit to the size reduction, etc. As we stopped using these materials the specialized FP parts like all kinds of sizes of reducing Tees quit being manufactured and so here we are. Time s change. My '41 Power Wagon had an electric starter (the kind you engaged by pushing the bendix gear into the flywheel) and a hand crank. Steamships had masts and sails for years after they were redundant. In both cases the old stuff faded away and the moderns of their day laughed at and wondered why.
On Thu, Feb 9, 2012 at 10:48 AM, Mike Hill <[email protected]> wrote: > Not sure what the original reasoning was. Cost and availability of 5" is an > issue now. Cheaper to use the much more readily available 6" offerings. > > On a side note: There is a building I know of near my office that we do > work > in regularly, I send my designers there to survey the existing system (it > is > pipe scheduled) just to see if they pay attention to the sizes. Most get > the > 3.5" and 5" wrong. I use it as a learning tool. > > Mike Hill > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Justin Reid > Sent: Thursday, February 09, 2012 12:34 PM > To: [email protected] > Subject: Re: Common Pipe Size Question > > I looked up fire protection couplings(random manufacturer) and did not find > any 3.5" couplings but they did have for 3" and 5". Is the lack > of use of 5" just cost versus benefit? Thanks for all of the > quick replies. > > Justin Reid > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC 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/20120209/de662f38/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
