What's the jockey set at? Isn't it typically higher? FWIW I'd flag you for the 3 psi too. They have no choice liability wise. If something ever breaks they (I) don't want the liability.
But I also understand it's only 7' up and the issue is resolved. As long as everything from the pump discharge to 7' above is high pressure listed I'd then be OK with it. Another issue is it's +3 today but what is the peak static pressure. Could be even higher in the future with normal sloshing of water in the city system. Chris Cahill, PE* Associate Fire Protection Engineer Burns & McDonnell 8201 Norman Center Drive Bloomington, MN 55437 Phone: 952.656.3652 Fax: 952.229.2923 [email protected] www.burnsmcd.com Proud to be one of FORTUNE's 100 Best Companies to Work For *Registered in: MN -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, February 18, 2014 1:50 PM To: [email protected] Subject: Static Pressure/Working Pressure 3.8.1.9.2 Static Pressure. The pressure that exists at a given point under normal distribution system conditions measured ... We have a project with an electric pump and when combined with the current water supply the churn pressure is 178 psi. A nationally known engineering firm wants us to install PRV's on the lowest level of the building because of the 3 psi. Our position is that the pressure only exists at churn and that is similar to an overnight pressure surge in a municipal water system. The over pressure will be compensated for by the pressure relief valves once the pump stops. Are we being overly loose with our interpretation of "normal" or is the engineering firm correct? Ron F _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
