The 30 psi does include elevation and friction. My guess is that the inlet pressure of the pump would be around 16-18 psi. No, the pump house is part of the main structure and cannot be moved.
At 08:31 AM 8/24/2011, you wrote: >Does the loss of 30 psi include the friction and the elevation loss? If not, >then you are getting pretty close to having cavitation at the pump inlet >and/or collapsing the supply pipe. > >Can you put the pump house lower on the hill? > >Matt Grisé PE*, LEED AP >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: [email protected] >[mailto:[email protected]] On Behalf Of Todd Williams >Sent: Wednesday, August 24, 2011 7:21 AM >To: [email protected] >Subject: Minimum pressures in water supply > >I am working on a new school project, where the building is 65 ft above the >water supply in the road and 760 ft horizontally. The water supply is >54-46-1130. There is a pump planned, which I have to size. The total pressure >loss in the underground between the supply and the pump house is approximately >30 psi. I know the general consensus (and some water company requirements) is >that the water pressure not be drawn down below 20 psi. A 500 gpm at 60 psi >pump would be a good fit for this project, but the suction pressures at the >pump would end up being below 20 psi. The supply in the public mains would >remain above 20 (due to the elevation), but would be below that in the private >main at the pump room. Any thought if this would be acceptable? > >Todd G. Williams, PE >Fire Protection Design/Consulting >Stonington, CT >860.535.2080 >www.fpdc.com > >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum Todd G. Williams, PE Fire Protection Design/Consulting Stonington, CT 860.535.2080 www.fpdc.com _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
