Ah! Thanks Jeff, that's pretty much what I was looking for and is good in this case where the PRV is close to the fire pump! Thanks,
--- On Wed, 6/20/12, Jeff Garrison <jeffgarrison1...@gmail.com> wrote: From: Jeff Garrison <jeffgarrison1...@gmail.com> Subject: Re: Calculating Pressure Reducing Valves To: sprinklerforum@firesprinkler.org Date: Wednesday, June 20, 2012, 10:55 AM In HydraCalc you can give a fixed PSI "limiter" to a fire pump, it will flat-line the curve above that PSI. On Tue, Jun 19, 2012 at 5:54 PM, Vince Sabolik <vi...@wtfp.net> wrote: > I've done this a couple of times before - for GSA, no less. > > Believe it or not, part of that dramatic pressure drop across that valve > IS friction loss. > The manuacturer will usually give you a loss table. In my case I showed > that loss (friction) in the appropriate > column and let the less be a fixed drop. > > Hope this makes sense > > At 05:03 PM 6/19/2012, you wrote: > >> I have an existing install that needs to be re-calculated due to some >> modifications. The system has a booster pump and downstream of the >> discharge, before the feed main disappears into the structure, there is a >> pressure reducing valve which is sett to 150 psi. I would like some >> confirmation that I'm calculating this thing right (hydracalc). >> I've set up a couple of nodes for the PRV and for the first run I set the >> friction loss at 0 to get an idea of what the discharge pressure is at the >> point of the PRV. Then I basically go back and enter in the difference of >> the pump net pressure and the PRV setting of 150 psi as the fixed friction >> loss through the PRV's nodes. So for example, let's say the pump is capable >> of 200 psi at my system demand and the PRV is at 150 psi - I set the fixed >> friction loss at the PRV to 50 psi to achieve the pressure reduction. Does >> this sound about right? >> >> This is more of a software question than anything I suppose but any input >> is appreciated. >> Thanks! >> RB >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://fireball.**firesprinkler.org/mailman/** >> private/sprinklerforum/**attachments/20120619/158d91e4/**attachment.html<http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120619/158d91e4/attachment.html> >> > >> ______________________________**_________________ >> Sprinklerforum mailing list >> Sprinklerforum@firesprinkler.**org <Sprinklerforum@firesprinkler.org> >> http://fireball.firesprinkler.**org/mailman/listinfo/**sprinklerforum<http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum> >> >> __________ Information from ESET NOD32 Antivirus, version of virus >> signature database 7233 (20120619) __________ >> >> The message was checked by ESET NOD32 Antivirus. >> > > > Vince Sabolik, West Tech Fire Protection, Inc. > 11351 Pearl Road / Strongsville, Ohio 44136 440 238-4800 Fax 440 > 238-4876 > ______________________________**______________________________**________ > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://fireball.**firesprinkler.org/mailman/** > private/sprinklerforum/**attachments/20120619/3fd6cb22/**attachment.html<http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120619/3fd6cb22/attachment.html> > > > ______________________________**_________________ > Sprinklerforum mailing list > Sprinklerforum@firesprinkler.**org <Sprinklerforum@firesprinkler.org> > http://fireball.firesprinkler.**org/mailman/listinfo/**sprinklerforum<http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum> > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120620/ba9609f2/attachment.html> _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120620/d894b449/attachment.html> _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
