You will need to see if between the elevation and the fittings and valves you drop to acceptable pressure at the floor control valve.
I have run in to this but its usually a big building and by the time I get to the connection I'm below 175. -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Ben Young Sent: Thursday, April 28, 2016 7:41 AM 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-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
