Unless the water purveyor or local ordinance has a 20 psi minimum requirement, there's no reason they'd have to provide a safeguard. It's a common limit, but it's a rule of thumb unless codified as it's not in most of the common building codes and standards. That said, if they have pressure to spare, a low suction control valve would be the way to go if you want or need to maintain 20 PSI or more for safety and have room to repipe the discharge side (and pick up a sensing line on the suction side).
Mike Morey, CFPS, SET Planner Scheduler/Designer BMWC Constructors, Inc. 1740 W. Michigan St, Indianapolis, IN 46222 O: 317.651.0596 | C: 317.586.8111 mo...@bmwc.com | www.bmwc.com ________________________________________ From: Sprinklerforum <sprinklerforum-boun...@lists.firesprinkler.org> on behalf of Todd Williams <fpdcdes...@gmail.com> Sent: Tuesday, February 16, 2016 7:41 AM To: sprinklerforum@lists.firesprinkler.org Subject: Oversized fire pump I am working on a facility with a fire pump that was oversized for the available public water supply. The pump is 1500 gpm at 85 psi. At 1500 gpm, the suction pressure drops to 18 psi. This is characteristic of the water supply and is not due to a shut valve or other obstruction. The pump was installed in 2009. Are there any safeguards that I should recommend for this situation? Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT 860-535-2080 (ofc) 860-608-4559 (cell) Sent using CloudMagic [https://cloudmagic.com/k/d/mailapp?ct=ti&cv=6.0.64&pv=8.2] _______________________________________________ Sprinklerforum mailing list Sprinklerforum@lists.firesprinkler.org http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list Sprinklerforum@lists.firesprinkler.org http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
