And so the only thing you can really count on is that at any given time the supply will likely not be what it was at the time of the test. How is it that all those old pipe schedule systems worked so well? Over built? They used to have more stable water systems? Are we over doing this? Under doing it? Pumps and tanks? To quote Kang and Kodos, "Abortions for some, miniature American flags for others, and pumps and tanks for all."
On Wed, Sep 23, 2009 at 3:08 PM, Todd Williams <[email protected]> wrote: > The converse of this is a community where the water company upped the > pressure 20 psi and now all the pumps are putting out 195 psi at churn.... > > > At 06:05 PM 9/23/2009, you wrote: >>This highlights the importance of taking into account all of the >>variables that can affect a water supply as outlined in NFPA 13 and >>Ron's earlier discussion about safety factors. We have a situation >>where the local water purveyor conducted the water flow tests. They >>noted that they have a gravity-fed system with booster pumps to >>maintain tank elevations. But they didn't believe the booster pump >>operations would affect the water supply much at our site. >> >>During fire pump acceptance testing we learned that the available >>supply was no longer as strong as we originally thought. After >>extensive searching for closed valves, retesting while city pumps >>were off as well as when they were running, we still are not certain >>why there is a weaker supply at the site than earlier in the year. >>But it appears that the city booster pumps must have been running >>during our original test, because they do improve the current supply somewhat. >> >>The point is, water supply testing and analysis is more critical >>than we normally recognize. How many times do you see folks taking >>a random flow test and designing to little or no safety >>cushion? Never mind the absolute idiocy of the ignorant PEs who >>allow competing contractors to conduct their own tests during the >>bidding process and then trust that the low bidder: 1) Tested >>correctly; 2) Accounted for normal fluctuations in the supply; >>3)Isn't modifying the results to get a more favorable outcome for >>their bid price. >> >>I don't know all of the specifics of this case, but it seems to me >>the AHJ isn't responsible. If this was an "engineered" project that >>went to competitive bids, it's the engineer of record's >>responsibility to have considered the potential changes in the water >>supply. If this was a negotiated project, then the sprinkler >>contractor should have allowed for changes in the supply. Of >>course, it's possible that there were changes brought about by >>unforeseen circumstances - like George's bottle plants that took up >>significant water. >> >>Mark A. Sornsin, PE >>Fire Protection Engineer >>Ulteig Engineers, Inc. >>Fargo, ND >>Direct: 701. 280.8591 >>[email protected] >> >> >>-----Original Message----- >>From: [email protected] >>[mailto:[email protected]] On Behalf Of Greg McGahan >>Sent: Wednesday, September 23, 2009 3:20 PM >>To: [email protected] >>Subject: Inadequte Water >> >>Just fielded a question from an AHJ in a nearby community about >>being sued by an angry building owner that is saying the water >>pressure is inadequate for the sprinkler system. (Static pressure >>has fallen 5 psi since construction). >> >>If any of you have specific experience with a situation like this I >>would like to be able to help him with some stories. >> >>Greg McGahan >>Operations Manager >> >>Living Water Fire Protection >>1160 McKenzie Road >>P.O. Box 877 >>Cantonment, Florida 32533 >>(850) 937.1850 | Fax (850) 937.1852 | Cell (850) 554.3231 >>[email protected] >> >>_______________________________________________ >>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) > > Todd G. Williams, PE > Fire Protection Design/Consulting > Stonington, Connecticut > www.fpdc.com > 860.535.2080 > _______________________________________________ > 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) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, WSAFM _______________________________________________ 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)
