I thought you didn't factor FDC pressures when selecting sprinkler components. If so, why are we not using high pressure sprinklers on all jobs.
Travis Mack, SET MFP Design, LLC "Follow" us on Facebook: https://www.facebook.com/pages/MFP-Design-LLC/92218417692 Send large files to MFP Design via: https://www.hightail.com/u/MFPDesign Sent from my iPhone > On Apr 28, 2016, at 9:40 AM, Ben Young <[email protected]> wrote: > > So the main answer appears to be yes, even with a wet manual standpipe, the > FD pumper pressure has to be considered for the sprinkler system when > configured in this way. > > Anyone disagree with this? > > > Benjamin Young > > On Thu, Apr 28, 2016 at 10:51 AM, Steve Leyton <[email protected]> > wrote: > >> The simplest (though possibly not the lowest cost) solution is to run a >> separate sprinkler riser instead of a combined system and install two FDC's >> - one for A/S and one for standpipes. >> >> My opinion only, >> SL >> >> -----Original Message----- >> From: Sprinklerforum [mailto: >> [email protected]] On Behalf Of Ben Young >> Sent: Thursday, April 28, 2016 7:47 AM >> To: [email protected] >> Subject: Re: standpipe and sprinkler pressures >> >> Steve, >> >> Its in design, but its a moot point at this junction for that particular >> project, because we increased the pipe size from the FDC anyway. >> >> So this is a hypothetical that is an exaggerated real scenario. >> Basically something to keep in the back of my mind for future projects >> where sales or another entity may want to try and squeeze down standpipe >> feeds to 4" even on a job with only two standpipes. What's that take, a >> 3-way siamese that has a 4" outlet? >> >> >> Tom et al, this is only a wet automatic system, the fire pump is >> irrelevant for the standpipe pressures. since the FDC is downstream of the >> pump, you don't have to size the pump (even in GPM) to match the standpipe >> demand. A lot of people at my company thought that so I think its a common >> misconception. >> >> >> >> >> Benjamin Young >> >> On Thu, Apr 28, 2016 at 9:02 AM, Steve Leyton <[email protected]> >> wrote: >> >>> When you ask, "Say you have a fully sprinklered building ...", do you >>> already have this building or is it being designed? >>> >>> >>> Steve >>> >>> >>> -------- Original message -------- >>> From: Ben Young <[email protected]> >>> Date: 4/28/16 4:41 AM (GMT-08:00) >>> To: [email protected] >>> Subject: standpipe and sprinkler pressures >>> >>> So this kind of came up earlier this week, and I've been researching >>> it and mulling it about in my head to no avail. I thought this would >>> be the best place to ask! >>> >>> Say you have a fulled sprinklered building with a combined standpipe >>> and sprinkler system. Building is non-highrise so standpipe is class >>> I wet manual, five standpipes total, so 1000 GPM is required at the >>> FDC. So good so far, right? >>> >>> There's also a fire pump for the sprinkler system, but that shouldn't >>> factor into the pressures for the standpipes... >>> >>> So I know that the FDC as it pertains to the sprinkler system side of >>> things is considered supplemental, and thus I don't have to worry >>> about excess pressures as long as my pump doesn't churn over 175 PSI... >>> >>> But what about when its to pressurize the standpipes? >>> >>> >>> For this scenario, lets say that even with 6" pipe from the FDC to the >>> standpipes (the first split point where 250 GPM breaks off) you still >>> need >>> 200 PSI at the FDC to enable 100 PSI at the top of the most remote >>> standpipe, and the fire department and AHJ has allowed this. >>> >>> Do I now need to verify that my sprinkler systems aren't seeing more >>> than >>> 175 PSI (if I'm using normally rated sprinklers and other various >>> valves that are only listed to 175)? Do I also need to use a pressure >>> regulating hose valve for the first few hose valves that would also see >> over 175 PSI? >>> >>> Or do you just say 'eh its a manual standpipe' and don't worry about it? >>> >>> >>> This has to have come up for others before, I've just never had to >>> deal with it I guess. >>> >>> >>> (Hmm, so apparently Tyco is the only slouch that doesn't have a floor >>> control assembly listed for pressures over 175 PSI...) >>> >>> Benjamin Young >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl >>> er.org _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl >>> er.org >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
