It is still early for me - so I cannot guarantee 100% brain power behind this...
I would say that the HP deficit could definitely cause your flow shortage. The work that the motor puts in results in water flow and water pressure. You can get more flow OR more pressure for the same HP, but if you want more of both it takes more power. (for a fun time, read that sentence with Mr Scotty's voice when captain Kirk asks for warp 7) Also - lots of pump literature will also include a horsepower demand curve under the pressure/flow curve. If it is there, you might line up 30 hp against the flow curve and see where you end up. Matt Grisé PE*, LEED AP, NICET II Sales Engineer Alliance Fire Protection 130 w 9th Ave. North Kansas City, MO 64116 *Licensed in KS & MO 913.888.0647 ph 913.888.0618 f 913.927.0222 cell www. AFPsprink.com -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Tim Stone Sent: Wednesday, November 12, 2014 7:16 AM To: [email protected] Subject: RE: pump replacement issue Todd, Does the pump meet the sprinkler demand? I would contact the manufacturer and discuss with the test department. Regards, G. Tim Stone G. Tim Stone Consulting, LLC NICET Level III Engineering Technician Fire Protection Sprinkler Design and Consulting Services 117 Old Stage Rd. - Essex Jct., VT. 05452 CELL: (802) 373-0638 TEL: (802) 434-2968 Fax: (802) 434-4343 [email protected] -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Todd - Work Sent: Wednesday, November 12, 2014 7:49 AM To: [email protected] Subject: pump replacement issue I was asked to witness a pump test on an installation where a new 500 gpm at 54 psi VT fire pump had been installed on an existing diesel driver. The churn and rated flow curves were OK, but we could only get a maximum of 650 gpm out of the pump (at a pressure consistent with the expected curve). Any thoughts as to why this would happen? The thing I noticed in the pump literature is that the "test motor" was rated at 50 hp and the site motor is 30 hp. Both of these were indicated on the literature. Could the difference in horsepower (even though RPM was the same) be the reason? The pump is a Xylem-AC Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT www.fpdc.com 860-535-2080 (ofc) _______________________________________________ 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 _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
