If the pressures are substantially different, I would check both. You will want to be sure that the PRV reduces the pressure enough when there is low flow, but not too much when the residual pressure is lower due to high flow. Also - if that PRV supplies the fire sprinkler system on that floor, you will want to check that it works ok for the range of flows needed by the sprinklers system (one head up to full calc).
Matt Grise On Tue, Oct 31, 2023 at 5:54 AM Micah Davis <[email protected]> wrote: > Good morning, Forum! I hope everyone is having a great week!! > > I think I got this right, but someone is questioning me. I have an > automatic standpipe with factory pressure-regulating valves (i.e., Zurn > 4000). When calculating residual pressures at the inlet of the PRV to be > used in the sizing charts, the question is, how much water should I be > flowing in the system? One suggestion is only flowing 250 gpm at the hose > valve you are sizing. The other suggestion is flowing the system demand > flow per NFPA 14. In this case, that would be 750 gpm (250 gpm at each of > the two most remote hose valves plus 250 gpm at the top of the only other > standpipe). We are in agreement that the calculation should be a source > calc to determine the actual pressure provided by the system. > > Thank you, > Micah Davis > Ferguson Fire Design > > _________________________________________________________ > SprinklerForum mailing list: > https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org > To unsubscribe send an email to > [email protected]
_________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]
