Are the city pumps redundant? Will the water utilities and/or fire department vouch for those pressures as normal operating conditions? Most of San Diego County is relatively new (sub-50 years) infrastructure, so this situation isn't unheard of around here. In checking with the water department, we have consistently found that their position is that the pump system is regularly exercised, backed up, and highly unlikely to fail. Serving fire departments generally concur.
To be on the safe side, take a 10% drop from static at your flow rate and call it a day. SL -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Brian Harris Sent: Tuesday, December 14, 2010 8:03 AM To: [email protected] Subject: Flow Test With City Pump Just did a flow test for a new project and the static was 100psi, opened the hydrant and the residual dropped to 50psi for a couple of seconds and then the city pumps kicked on and the residual went to 110psi. When doing the calc's for this system wouldn't you need to do it without the boost from the pumps? (S=100 R=50) If that is the case what do you do for the flow as the pitot reading was done after the pumps kicked in? Brian Harris First Defense Fire Protection 11957 Ramah Church Road Huntersville, NC 28078 Phone: 704.948.3506 Fax: 704.948.3507 Nicet # 128476 ======= Email scanned by PC Tools - No viruses or spyware found. (Email Guard: 7.0.0.21, Virus/Spyware Database: 6.16510) http://www.pctools.com/ ======= _______________________________________________ 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)
