Maybe it's a mistake? Like the check in the bypass between the two valves? I know you always put a valve on each side and keep the diameter spread for turbulence. They do work, not highly accurate imho but they save using water once every three years (or is it five). Tom
I haven't seen any in over 50 years. Of course, I have only been paying attention for the last 27. At 06:30 PM 3/18/2009, you wrote: >In my 26 years in the Industry I have never installed one in the >closed meter loop or designed one with a check valve. Why would NFPA >'Pumps for Fire Protection Sytems' by Kenneth E. Isman, P.E. & >Milosh T. Puchovsy, P.E. state that. > > >George Medina Jr. > > >Perhaps your speaking of a check valve is required on the >discharge side of the FP. The meter loop just circulates >water back to the pump and shouldn't have anything to do >with city supply. Look at the example configuration in the >appendix for your locations of checks required. As far as >the text, I don't have NFPA-20 (2002) we still use 99. >Personally I have never used or seen a check valve on the >meter loop in 30+ years. > >Don Lowry, >Dickerson Fire Protection > > >NFPA No.:Z4Pump02 page 108 - States that a check valve is >required on the discharge side of flow meter. Our union >field guys state they never put one on?there. Is this >correct? >I believe a flow meter would be damaged from positive city >pressure back flowing through the meter after shutting down >the pump and before closing the isolation valve. Somebody >correct me for being wrong. > > >George Medina Jr. _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
