What testing has shown that the old EQ requirements were insufficient? I would surmise that Northridge was what got everybody squirrelly but according to the report those "failures" weren't directly caused by insufficient bracing. Maybe more bracing would have distributed loads over more attachments but if I recall correctly all two hundred plus failures were attributed to either c-clamps walking off beams resulting in too much unsupported weight for the pipe itself to stay up (kind of like when your suspension bridge fails) and not an EQ bracing issue at all, or pull out of powder driven fasteners and lags. In the case of powder driven fasteners I think I read that the problem stemmed from either too little of a load, too much of a load, or an improper angle of attack. In the case of the lags each failure was attributed to not having drilled a pilot hole so that the fastener was just compressing fibers rather than cutting into the wood. These are installer problems, not sufficiency of design issues. I guess my question is are the latest and greatest really necessary if the installation is properly done or is it a reaction to the results of an event rather than the cause?
On Thu, Mar 20, 2008 at 12:03 PM, Roland Huggins <[EMAIL PROTECTED]> wrote: > Here's what ASCE 7 requires: > > Cat C: NFPA 13 deemed to meet the other requirements of ASCE 7 > > Car D, E, or F: All of the following must be met. > > 1. Hanger and bracing accepted if BOTH of the following are met: > A. NFPA 13 and > B. Force and Displacement of ASCE 7 > > 1-B effectively kills the idiotic criteria in 13:9.3.5.6.3 whereby Cp > of 0.5 is applied IF the AHJ does not specify what seismic load is to > be used. Hmmmmmm how would the AHJ know the LOAD since that would > require knowing what pipe is in the assigned zone of influence. You > think maybe they should have said Cp or Ss? Well that's a different > story. > > 2. The piping shall meet the force and displacement defined by ASCE 7 > > 3. The design strength for the sprinkler piping shall be based on a > reduced yield strength for steel and copper and a reduced tensile > strength for plastic > > Also already pointed out, NFPA 13 and Ss for up to 3.0 (berry , berry > high whereas even the fire rim doesn't see it lol). 13 also has a > reduced maximum spacing of braces based on the pipe size and > assigned load as well as reducing the spacing of restraint based on > the pipe size and assigned Cp (which must be assigned by the > applicable Ss noting the comment on 1-B) > > I have ASSUMED that 13 has taken this into account due to the reduced > spacing but can not attest to that fact YET. I have asked the AFSA > reps on 13 Hanging and Bracing this question as well as Jim Lake > (NFPA). Will respond when they answer (and I find out what part of > assume applies). > > Roland > > On Mar 20, 2008, at 11:13 AM, Roland Huggins wrote: > > > I would say it is NOT an NFPA question but a building code question > > since it defines what can be used when. I don't remember the > > specifics off the top. To avoid the extreme measure of actually > > opening that book, does anyone else know off the top? > > > > Roland > > > > On Mar 20, 2008, at 10:15 AM, Charles Thurston wrote: > > > >> Hello Keith, > >> > >> A quick phone call to NFPA with a follow up email might be the > >> best way to > >> get a quick answer. > >> > >> Th > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > > > To Unsubscribe, send an email to:Sprinklerforum- > > [EMAIL PROTECTED] > > (Put the word unsubscribe in the subject field) > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > -- Ron Greenman at home.... _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
