DITTO George!!!!
Mike > From: [email protected] > To: [email protected] > Subject: RE: Pipe Size > Date: Wed, 12 May 2010 14:57:57 -0400 > > First, lessening the pressure differential between flowing heads on a line > will reduce overdischarge. > > 2nd, larger K-factor heads tend to accentuate overdischarge between flowing > heads. > > Keeping the original K factor while upping the end pces to 1.25", and likely > switching from Sch 40 to Sch10 in doing this, you'll have less demand if the > MRA is uniform. That's elementary hydraulics. And this is one of those > occasions when I'm glad I had to learn hand calcs, cause if you don't > understand the interrelationship of the variables, you'd spend an hour or > two going the wrong way- instead of making a quick change, hitting CALC, and > seeing the result go up or down. > > Yes, I'm aware of what happens in irregular MRAs. Did a presentation years > back on this, where tossing in a couple 90's on a BL n the MRA caused a 2 > PSI increase in demand for that line, a contractor could argue that the 5 > PSI cushion covered this. Except that this was the only line in the MRA > with the added offsets, so virtually every other head in the MRA > overdischarged, and it was a 7 PSI impact to the MRA, and the 5 PSI buffer > went to 2 PSI over the curve. I believe some of the plan reviewers in the > room followed my point. The inspectors had been asleep for an hour, once the > seminar moved to hydraulics. > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Russell > Sent: Wednesday, May 12, 2010 12:19 PM > To: [email protected] > Subject: RE: Pipe Size > > Well, what I'm getting at is that the more water that is flowing from the > remote area the less residual pressure you have available at the source. The > less residual, the less the safety factor. The same as trying to use > sprinklers with a k-factor of 8.0 in a light hazard design. It'll kill your > calc's. > > Russell > > _______________________________________________ > 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) _______________________________________________ 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)
