Instead of attempting to discern some logical reason why a hose stream is not required, let's look at the big picture. ALL storage require a hose stream but this one line in Table 16.2.2.1(a) for the Class I- III 20 ft storage in 35 ft bldg . ALL large drop table require a hose stream except this one line. All places in ALL large drop tables showing an N/A for hose stream also have an N/A for number of sprinklers except this one line. We could draw the conclusion that can we use a dry system for this one line but I suspect most will conclude that a typo occurred and there is SUPPOSE to be an N/A on the number of sprinklers too.
The moral of the story when trying to apply logic to an otherwise illogical fact, look at the whole forrest and not just the one tree. I'll notify Mr. Lake so that either an errata or a TIA is forth coming. Roland On May 19, 2009, at 10:16 AM, A.P.Silva wrote: > Do you mean with with the increased number of sprinklers, hose > stream can't > be provided? Or not required? I'm confused, so I hope you can expand. > > Take Class I,II,III commodities 25 ft. storage height, 35 ft. ceiling > height, dry system, Number of sprinklers = 25 + 1 level of in-rack, > Hose > Stream = 500 > > Whereas, same commodities, 20 ft storage height, 30 ft ceiling > height, dry > system, number of sprinklers = 25, but hose stream = N/A (or NCD) > > The extra 10 sprinklers (comparing dry to wet) at 25 psi, works out > to 560 > gpm (using k=11.2 heads). A little over the wet system Hose > allowance for > both cases. Do you mean the hose stream is already included in the dry > system? In which case, there won't be much difference in the demand > between > wet and dry, if galvanized piping is used. Nothing to account for > the dry > system delay? > > Tony > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Roland > Huggins > Sent: May 19, 2009 8:31 AM > To: [email protected] > Subject: Re: Large drop sprinklers > > Hose stream N/A matches the number of sprinklers N/A making it a NCD > - No > Can Do > > Remote area: look at 22.4.4.2 > > Roland > > On May 18, 2009, at 4:07 PM, A.P.Silva wrote: > >> NFPA 13, 2002 table 12.3.2.2.1(a) or >> NFPA 13, 2007 table 16.2.2.1(a) >> >> Large Drop Sprinkler Design Criteria for ........Class I through >> Class >> IV Commodities ..... >> >> Two questions: >> >> (1) Hose stream allowance for some storage configurations with dry >> systems are given as "not applicable". Why? >> (2) Number of design sprinklers are given. But not how many on a >> line. >> I guess a design rectangle can be worked out, but is that the intent? >> >> Tony >> >> _______________________________________________ >> 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)
