No tank pr pump since the water supply is strong with 2500 gpm available. The reduced pressure had the developer upsize the mains to a 12" loop and 10" lead-in to the riser with 1900 GPM. His hydraulic program appeared to be an AWWA supply system. With the larger pipe the 50 psi require pressure was available.
Roland wrote: The FPE may have adopted the idea from Montgomery County, MD. SInce they identify the water supply and modified it such that it can not support the job, did they spec a tank and pump as part of the job? On Sep 29, 2008, at 6:51 AM, Arthur Tiroly wrote: > > > > Dear Forum, I will try this again. > > On several projects we are finding engineered water supply > availability > coming from the major chain store's [art] FP engineers. Recently the > engineer used a city water flow test from a Cleveland 16" supply and > assumes > that the closest elevated water tank is empty and reduces static and > residual by 30 ft = 13 psi. That becomes the new flow test for > hydraulic > calcs. He calls this the due diligence water supply for hydraulic > calcs > > Even good water supplies become inadequate for some of the bigger > box stores > with flow demands of 1500-2000 gpm. This is NOT Walmart, Lowes or Home > Depot. Where are these requirements to down grade a water supply > coming > from? Should this be the norm? Then we need a 10 psi cushion to the > reduced > residual. > Is this the insurance company requirement? > [art] > Comments please. > > Art Tiroly > > _______________________________________________ > in the subject field) _______________________________________________ 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)
