That's why NFPA 25 is changing the requirement to drain the low points to multiple times and don't stop until prior efforts to drain show no more water.
Roland On Jan 8, 2010, at 1:59 PM, Mark Sornsin wrote: > I have a client with a parking garage. Large enough for two dry- > pipe systems. Each are piped relatively flat (pitched per NFPA 13, > but no more); each on a big loop of 4 in main with side feed branch > lines out the side of the mains. > > This system was last flooded last summer (say August). Since that > trip test and subsequent draining, the client has blown out all 6 > low point drum drips twice a month, every month. But even still, > over Christmas, and only two weeks after blowing out the drum drips, > they froze 4 of the 6 drum drips to the point of breakage - 3 of the > 6 were filled with ice throughout the 2 in. x 12 in. drum, and up > the 5 or 6 ft. of 1 inch pipe. > > The contractor that replaced the drum drips noted that there was no > appreciable water on top of the dry valves, so the water in the > pipes appears to be entirely from condensate. Or maybe, somehow, > residual from the trip testing 5 months ago (???). > > Has anyone of you seen this amount of condensate coming from a dry > system? The air compressors are floor mounted with no tank. The > riser room is somewhat damp (large sump pit located here, too) and > maintained at about 55 degrees. But I still have a hard time > imagining how that much water could come from condensate. > > Any thoughts? > > > Mark A. Sornsin, PE > Fire Protection Engineer > Ulteig Engineers, Inc. > Fargo, ND > Direct: 701. 280.8591 > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.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 [email protected] http://fireball.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)
