Seeing how NFPA 13 defines a system riser as an above ground horizontal or vertical pipe **between the water supply and the cross or feed mains** that contains a control valve etc... I would say your option 'A' would be the best fit for a manifold system. For a single riser it makes sense that BOR is at the supply flange, 6" A.F.F.
On Fri, Aug 21, 2015 at 7:31 AM, Ed Kramer <[email protected]> wrote: > This may have been discussed previously, I don't recall. > > Assume an underground fire service enters a building, multiple system > risers are located in an interior mechanical room approx 50' from the > stub-in location. In the mechanical room there is a backflow prevention > device and multiple system risers. Where is the "base of riser" - you > know, > the "base of riser" that listed on the hydraulic design placard? > > a) At the bottom of each individual system riser - a slightly > different > physical location for each system? > > b) At the discharge side of the backflow prevention device? > > c) At the inlet side of the backflow prevention device? > > d) At the underground flange? > > > > I'm curious how others see this. > > > > Ed Kramer > > Lawrence, KS > > _______________________________________________ > 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
