And it may not be a gravity system, don't know where you are but we run into jobs located down the hill from a building we did and find less, not more pressure due to a PRV waterco has installed.
Then there's pumping stations, so barring a system that's straight tank(s) and gravity, anything can happen. A little friendly banter about wht they have with t heir distribution foreman can quickly bring an AHA! experience. I was puzzled by a 120 static, 70 at 353 gpm report I got with 12" mains off 16" mains- till I asked about 4 or 5 questions, then observed there had to be 10 miles between tank and test to get that much drop, and he said no- it's 1,353 gpm. Oh! Yea, that makes sense....duh. glc -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Fletcher, Ron Sent: Tuesday, June 23, 2009 3:56 PM To: [email protected] Subject: RE: Hydrant Flow test results If it's a municipal water supply the two graphs will probably not be the same. The graph isn't from a zero flow to the 2.5" flow and then the 4.5" flow. If there was 2,000 gpm domestic flow at the time of the test the graph is actually from 2,000 to 2,000 plus the 2.5" flow or 2,000 plus the 4.5"flow. The N1.85 graph we use doesn't take the domestic demand into account. Ron Fletcher Aero Automatic Sprinkler 21605 N. Central Ave Phoenix, AZ 85024 P: 623.580.7836 F: 623.434.3420 C: 602.763.4160 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Paul Pinigis Sent: Tuesday, June 23, 2009 12:33 PM To: [email protected] Subject: RE: Hydrant Flow test results Any single-hydrant test is questionable to begin with, but if two tests are done they should yield identical graphs. Pitot pressures of less than 10 psi are generally unacceptable. Paul Pinigis, P.E. Life Safety Department Head -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Richard Lindner Sent: Tuesday, June 23, 2009 3:25 PM To: sprinklerforum Subject: Hydrant Flow test results Have a question regarding hydrant flow tests. We have received a report where the contractor flow a single 2 1/2" outlet and gave us static, residual, pitot and calculated flow. He then performed another test using the 4 1/2" outlet on the hydrant, again giving us values. Plotting the graph, is there supposed to be a correlation between the testing of the 2 1/2" versus the 4 1/2" or are they supposed to be used separately. For example, when graphing the 2 1/2" outlet, the 4 1/2" outlet info should be hitting this line or not?? Also, is a pitot reading of a range of 4 to say 8 on a 4 1/2" outlet valid data? We're not sure how to use this info. Richard _______________________________________________ Sprinklerforum mailing list http://lists.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 http://lists.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 http://lists.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 http://lists.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)
