I'm curious where the 30 minute fill came from. Convenience to FDs? I'd certainly not want my highly paid and trained engine company hanging around for a couple of extra hours to watch the system fill. But if I'm likely have the service guy from the sprinkler company, or even my owned trained maintenance, hanging around, and I'm willing to pay for him to watch the paint dry, and I'm so concerned with my system as to have bought a nitrogen generator instead of using that nasty moisture holding air, why not ignore that code section? Or is the 30 minute rule there just because we needed a definitive time frame and 30 minutes sounded reasonable at the time? Or is there another, more compelling reason? Curious minds want to know.
On Fri, Oct 5, 2012 at 6:07 AM, Tom Duross <[email protected]> wrote: > Most generators, if not all, have a nitrogen storage tank. The one I used > put out 70 PSI requiring an AMD and we still had a riser mount air > compressor because the generator could not fill in 30 minutes. They're > interconnected and valved. > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Roland > Huggins > Sent: Thursday, October 04, 2012 5:44 PM > To: [email protected] > Subject: Re: Air Supply > > If you use nitrogen (7.6.2.7) it now kicks you over to 7.2.6.5 (Automatic > Air Maintenance). Must admit, I see no reason to use an air tank and > plenty > not to (as George already said). I'd say an air cylinder would be not > different than a nitrogen cylinder when it comes to requiring an AMD. If > you do not have a low pressure alarm, the pressure gauge has to be checked > weekly instead of monthly. Now that dry pipe system have to have an air > leakage test performed every 3 years, there shouldn't be any systems (or at > least as many) needing a compressor running full time to keep it from > tripping. > > Roland > > On Oct 4, 2012, at 12:54 PM, Cahill, Christopher wrote: > > > Looking over a job where the EOR wants to use cylinders to supply the > > air for a dry system. There is plenty of power to the building so > > that's not the issue. They are showing lab air cylinders from both > > air (NC) and nitrogen (NO) into an AMD into the system. I get > > automatic air is not required. But I'm seeing NFPA 13 '12-7.2.6.5.1 > > limiting air supply when AUTOMATIC to dependable shop system or a > > compressor. I don't see bottles being allowed. Or that is to say I > > don't see bottles as being a dependable shop system. > > > > I assume some of you have done bottles for the air to a dry system? > > As I read you can have them if someone manually opens a valve and > > refills the system when needed? Of course this is even confusing. > > Is there something on a manual fill system that requires daily > > checking? Or are they relying on the low pressure alarm to note when > > time to refill? Actually, the low pressure alarm isn't even required, > > right, so are they waiting for a system trip to know when to add air? > > > > If manual is allowed isn't an AMD off a bottle a little better but not > > quite the full blown compressor? Why would they restrict the middle > > on the order of worst to best? > > > > Who wants to straighten me out 'cuz none of us here have ever seen > > bottles used on a system? > > > > Chris Cahill, PE* > > Senior Fire Protection Engineer, Aviation & Facilities Group Burns & > > McDonnell > > > > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20121005/6c848fa4/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
