Actually the fitter story is referenced in the Handbook commentary (9.1.1.2 - 2002)
At 11:39 AM 8/4/2009, you wrote: >I don't know if that extra 250 lbs was really for the fitter of old to >grab onto or if that is just the story we've been telling each other >for so long it's become the common "truth." If the truth then we'd >better reassess it in light of current times. First we need to add >about 100 lbs if it's to meet the criterion of the story but, and >probably more telling, I think OSHA (or your local version) might be >concerned if we're actually telling our fitters to grab the piping if >they fall. Adding the 250 lbs is the rule. Why is unimportant unless >the hanging and bracing committee wants to revisit the rule. If >research were to suggest that the "story" really is the "truth/reason" >then maybe we can just let it go. And what really is the criteria for >any of this? Is it just a left over from the days of "I remember when >13 fit in your back pocket" versions of 13 that only addressed pipe >schedules and other good, safe rules of thumb? Who decided, when was >it decided, why is it (has it been constantly evaluated as valid--too >much or too little), what values is it based on, etc.? In any event at >this stage of sprinkler design development I'd worry about adding the >250 lbs to the calculation but not because a fitter might grab it. He >might just as easily reach out for the 1/2 inch conduit. Better to >have him properly tied off. Saves a heap of change on OSHA fines, >lawsuits and possible criminal charges. > >On Tue, Aug 4, 2009 at 8:09 AM, Todd Williams<[email protected]> wrote: > > Something to think about. Hangers are designed to take 5x wt of water > > filled pipe +250 lbs. The 250 is supposedly to support a fitter if he > > had to grab on to it in an emergency (or so I have been told). Has > > anyone looked into if CPVC pipe could support a 250 lb person, even > > with hangers designed for it? > > > > > > > > At 10:54 AM 8/4/2009, you wrote: > >>Why not just calculate the modulus using the methods in NFPA 13 and then > >>size your trapeze pipe accordingly. Or, as George said, use the values > >>for steel and just have some oversized trapeze bars. > >> > >> > Assuming CPVC weighs less than steel pipe, use values for > steel and you're > >> > safe. If you're near a head, make sure you're protecting against upward > >> > movement if needed. > >> > > >> > When we get into bar joist construction, we often switch to steel since > >> > hanging issues often make it a better installation all around. > >> > > >> > glc > >> > > >> > -----Original Message----- > >> > From: [email protected] > >> > [mailto:[email protected]] On Behalf Of > >> > [email protected] > >> > Sent: Tuesday, August 04, 2009 9:03 AM > >> > To: [email protected] > >> > Subject: Re: trapeze hanger, PVC > >> > > >> > Greg, > >> > If you are in a position to require trapeze hangers on > cpvc,maybe you need > >> > to reconsider using steel pipe for stability and rigidity.Just > a thought. > >> > ---- Greg McGahan <[email protected]> wrote: > >> >> Have we ever discussed the use of trapeze hangers for cpvc piping? > >> > Specifically, modulus requirements etc? > >> >> > >> >> Greg McGahan > >> >> Operations Manager > >> >> > >> >> Living Water Fire Protection > >> >> 1160 McKenzie Road > >> >> P.O. Box 877 > >> >> Cantonment, Florida 32533 > >> >> (850) 937.1850 | Fax (850) 937.1852 | Cell (850) 554.3231 > >> >> [email protected] > >> >> > >> >> > >> >> _______________________________________________ > >> >> Sprinklerforum mailing list > >> >> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > >> >> For Technical Assistance, send an email to: > >> >> [email protected] > >> >> > >> >> To Unsubscribe, send an email > >> >> to:[email protected] > >> >> (Put the word unsubscribe in the subject field) > >> > _______________________________________________ > >> > Sprinklerforum mailing list > >> > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > >> > For Technical Assistance, send an email to: > [email protected] > >> > > >> > To Unsubscribe, send an email > to:[email protected] > >> > (Put the word unsubscribe in the subject field) > >> > > >> > _______________________________________________ > >> > Sprinklerforum mailing list > >> > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > >> > For Technical Assistance, send an email to: > [email protected] > >> > > >> > To Unsubscribe, send an email > to:[email protected] > >> > (Put the word unsubscribe in the subject field) > >> > > >> > >> > >>-- > >> > >> > >>_______________________________________________ > >>Sprinklerforum mailing list > >>http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > >>For Technical Assistance, send an email to: [email protected] > >> > >>To Unsubscribe, send an email to:[email protected] > >>(Put the word unsubscribe in the subject field) > > > > Todd G. Williams, PE > > Fire Protection Design/Consulting > > Stonington, Connecticut > > www.fpdc.com > > 860.535.2080 > > _______________________________________________ > > Sprinklerforum mailing list > > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > > > To Unsubscribe, send an email to:[email protected] > > (Put the word unsubscribe in the subject field) > > > > > >-- >Ron Greenman >Instructor >Fire Protection Engineering >Bates Technical College >Tacoma, WA > >Member: >SFPE, ASCET, NFPA, AFSA, NFSA AFAA >_______________________________________________ >Sprinklerforum mailing list >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
