The water departments don't know about it because few if anyone would call and report low water pressure in their shower, they just deal with it. So if no one bothers to report a problem, there's no way they'll know.
Had a similar situation a few years back. Could not get a dry system to pass the trip test for the AHJ, we verified and reverified information given us, triple checked the installation and finally had another flow test performed and the numbers were all different. Had several tests done and numbers varied each time. Finally the water department came to a conclusion that based on various new users in their system, the flow data would fluctuate with no apparent consistency. But until we raised the flag, they had no idea that their system fluctuated so widely during any given day. Craig L. Prahl, CET Fire Protection Group Mechanical Department CH2MHILL Lockwood Greene 1500 International Drive PO Box 491, Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 [EMAIL PROTECTED] http://www.lg.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Todd Williams - FPDC Sent: Monday, October 01, 2007 4:30 PM To: [email protected] Subject: water supply fluctuation I just ran into a situation that makes me a little nervous about water department flow tests. I have been asked to straighten out a mess on a system in a 7 story condo (multiple issues). A designer who was asked to verify some hydraulics got a flow test from the municipality which was about 23 pounds higher than the design test, which was done several years ago. At that time, she was told this was due to improvements in the public system. They had been doing a lot of work on the system, so it was believable. System pressure gauges were with a reasonable number of the static pressure. When I got on board, I also checked with the water department and was told the same thing. Recently, a contractor working on the system noticed the the pressures reading lower. Upon further investigation, including pressure recorders on hydrants, it was found that the pressures varied 30 psi over a 3 day period. The water department was not aware of the range of fluctuation until they did this test. Their explanation was various pumps kicking in to fill tanks, including for the town's largest water user. Now we are going back and re-calculating the systems with a much lower static pressure. Has anybody run into this type of thing? Is there a good way to detect it? I consider myself fairly savvy and sniffing out problems, but this caught me off guard. How can a water department not know this type of thing is going on. This is a small city in CT. Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ 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) _______________________________________________ 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)
