I have done a few of these. I am not sure about 2019, but 2016 main and appendix describe how to do this. You are pretty much in the right track
> > On Apr 13, 2021 at 6:51 PM, <J H via Sprinklerforum > (mailto:sprinklerforum@lists.firesprinkler.org)> wrote: > > > > Any takers? Does anyone retrofit backflows onto pipe scheduled systems? On > Mon, Apr 12, 2021 at 2:43 PM J H <design.azfire...@gmail.com > (mailto:design.azfire...@gmail.com)> wrote: > Hello All, > We're > retrofitting a double check into an existing pipe scheduled system. > In > looking at NFPA 13 (2019) edition 19.3.2.1 in order to do this we just > > need a hydrant flow test and then subtract the friction losses of the > > double check and the friction loss due to elevation of the highest > > sprinkler from the flow test and make sure the leftover pressure is greater > > than the value of 19.3.2.1. Is that correct? > > JH > > > _______________________________________________ Sprinklerforum mailing list > Sprinklerforum@lists.firesprinkler.org > (mailto:Sprinklerforum@lists.firesprinkler.org) > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > _______________________________________________ Sprinklerforum mailing list Sprinklerforum@lists.firesprinkler.org http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
