The weight of water in feet is .4331 per foot. 57.7 feet x .4331 = 25 PSI. I think someone has the formula backwards.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ron Greenman Sent: Tuesday, April 08, 2008 11:13 AM To: [email protected] Subject: Re: Failed Bucket Test Ron, Check your math: 25.0 x 0.433 = 10.825 On Apr 8, 2008, at 8:47 AM, Fletcher, Ron wrote: > 25 psi equals 57.7 feet of elevation and partially closed valves can > account for a reduced static pressure when dealing with city water > mains. > > Ron Fletcher > Aero Automatic > Phoenix, AZ > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Ron > Greenman > Sent: Tuesday, April 08, 2008 8:32 AM > To: [email protected] > Subject: Re: Failed Bucket Test > > Brian, > > Static doesn't change, even with a blockage (recovery time is slower > but > eventually reaches the pre-recorded pressure--hence the value of a > main > drain test), unless the original test was done during off-peak and > your > bucket test was done during peak, there is a pump involved that is not > coming on or has been removed from service (your bucket test may not > have enough demand to fire it up but a hydrant test would--this begs > the > differences in static), the grid has been changed and the source, if > gravity, is lower, relative to the site, than before, the level of the > tank was lower during your test (25 psi equals a little less than 11 > feet) or the guy that produced the original numbers didn't know what > he > was doing (I got a report once that showed the residual pressure and > velocity pressure to be the same--the water guy wouldn't budge). If > you're in a residential area I'd look at the time of day and time of > year the test was done as well as the area, read grid, growth since > the > time the test was done. Mid day and mid night are off peak times as is > winter in general during peak. The tanks may be low and your test may > have been done during or at the end of morning peak or the beginning > of > evening peak. The original test may have been done during summer at > midnight when usage was down and the tanks freshly replenished for > tomorrow's lawn watering. Lots of possibilities. I think our reliable, > automatic water supplies are less than reliable but the alternative > seems to be stored water and pumps--extra equipment to fail. > > On Tue, Apr 8, 2008 at 7:22 AM, Brian Harris > <[EMAIL PROTECTED]> wrote: >> > > > > -- > Ron Greenman > at home.... > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email > to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) Ron Greenman ...at home _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
