What I was taught was that the effective point for a flow test is at the intersection of the flowing and non-flowing water. This is the point you should calculate from. This can vary given the configuration of the mains, hydrants, connections or whatever. Quite often this is at or near the gauge hydrant, but not always.
Interestingly, if you have a situation with a looped public main with 2 hydrants and a connection to a supply in the middle (0 elevation difference), the designer may not be far off. If you do a flow test with the gauge on one hydrant and flowing the other, then switch hydrants, the results will be close or exactly the same. That would mean that the supply at the connection in the middle would have the same characteristics as the tests. . This could be where he (or she) got the info. However, adding the the underground loss from the effective point would help with the inherent inaccuracies in our test procedures. Any deviation from the exact scenario above would or could throw this off. Elevation differences always need to be considered. Todd G Williams, PE Fire Protection Design/Consulting Stonington, CT www.fpdc.com 860-535-2080 (ofc) > On Jun 19, 2014, at 9:19 AM, Brian Harris <[email protected]> wrote: > > Was just told by one of our new designers that he was taught that it didn't > matter where the flow test was taken on the underground that you just need to > take it back to the tie in point at the main & that everywhere he's worked > does it that way. News to me, any of you guys do it that way? If so how do > you account for the loss in the underground to the test hydrant, elevation, > etc.... ? > > Brian Harris, CET > BVS Systems Inc. > Sprinkler Division > bvssystemsinc.com<http://bvssystemsinc.com/> > Phone: 704.896.9989 > Fax: 704.896.1935 > > _______________________________________________ > 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
