Your concerns are valid. I would recommend the water purveyor be involved. Carefully run the pump to 150%, with them there after they say dropping the supply to less than 20 is ok. Otherwise, it is an acceptance issue.
I have run into lower supply's that have caused me to fail systems, even without the pump. Fortunately, there were inspections tags noting the decline in the supply over a 10-15 year period. Like 3-5 psi a year due to infrastructure demand and development. Sounds like what you are looking at. Any records? R/ Matt Matthew J. Willis Project Manager Rapid Fire Protection Inc. *NEW ADDRESS* 1530 Samco Road Rapid City, SD 57702 Office-605.348.2342 Direct Line-605.593.5063 Cell-605.391.2733 Fax:-605.348.0108 -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Richard Carr Sent: Tuesday, February 16, 2016 6:07 AM To: [email protected] Subject: RE: Oversized fire pump NFPA 20, 4.14.3.1 tells me to be 0 or higher on the suction side. Richard Carr, SET Branch Manager Cox Fire Protection, Inc 6555 Grace Lane. Jacksonville, Fl. 32205 [email protected] 904-781-8227 -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Todd Williams Sent: Tuesday, February 16, 2016 8:01 AM To: [email protected] Subject: Re: Oversized fire pump My concern is that the 18 psi suction pressure occurs at rated flow. Since the pump has the capacity to flow at 150%, is there a danger of dropping the suction pressure dangerously low. The building is a hospital. 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] On Tue, Feb 16, 2016 at 7:52 AM, Richard Carr <[email protected]> wrote: If you maintaining 18 psi on the suction side with the pump running, why would you do anything? Richard Carr, SET Branch Manager Cox Fire Protection, Inc 6555 Grace Lane. Jacksonville, Fl. 32205 [email protected] 904-781-8227 -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Matt Grise Sent: Tuesday, February 16, 2016 7:42 AM To: [email protected] Subject: RE: Oversized fire pump How about a suction control valve? 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 913.526.7443 cell www. AFPsprink.com -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Todd Williams Sent: Tuesday, February 16, 2016 6:41 AM To: [email protected] 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 [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 _______________________________________________ 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
