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
