My understanding is that single hydrant tests are not as accurate as double hydrant flow tests. You are trying to figure out how much pressure you can get from the system when it is discharging a certain amount of water. If you test the flowing hydrant, I imagine the pressure would read lower since the water would have a pretty high velocity. (just thinking out loud there... I have not researched it)
Matt Grisé PE*, LEED AP Sales Engineer Alliance Fire Protection 130 w 9th Ave. North Kansas City, MO 64116 *Licensed in KS & MO 913.888.0647 ph 913.888.0618 f 913.927.0222 cell www. AFPsprink.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Smith, Steven D. (CSFD) Sent: Friday, July 22, 2011 10:41 AM To: [email protected] Subject: RE: Convert pitot to actual residual?? What if a pressure gauge was installed on the other outlet of the hydrant from which the water is flowed and pitot reading is taken? IOW, is it possible to have the test and flow hydrant one in the same? -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Vince Sabolik Sent: Friday, July 22, 2011 9:08 AM To: [email protected] Subject: Re: Convert pitot to actual residual?? Ron, Ron, Yeah figured so. I just thought that someone may have had one of those 'rule of thumb' thingys laying around. Seems to me THAT should be possible, no? I just wanted this to guestimate the design ahead of doing another test. BTW, sorry about the double posts. I'm having an argument with me this morning. At 10:58 AM 7/22/2011, you wrote: >Vince, > >Since you don't have a residual, which is the left over energy in the system >measured in psi at the non-flowing hydrant, while flowing through that >circular orifice you're screwed and the test has to be re-done. Once you >have actual flow and residual you can calculate flow at any residual >pressure (changes with the size of orifice) or residual at any flow. >Unfortunately static minus velocity (the pitot reading) doesn't equal >residual. Life and understanding the world would be so much easier if it ran >on magic and religion instead of physics. > >Vince Sabolik, West Tech Fire Protection, Inc. 11351 Pearl Road / Strongsville, Ohio 44136 440 238-4800 Fax 440 238-4876 ____________________________________________________________________ _______________________________________________ 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)
