Yeah, I think we're doing it the same way but you're taking the additional friction loss in the valve itself and adding that in and not just the pressure differential right? BTW, this is a fixed setting (diaphragm type) prv.
--- On Tue, 6/19/12, Vince Sabolik <[email protected]> wrote: From: Vince Sabolik <[email protected]> Subject: Re: Calculating Pressure Reducing Valves To: [email protected] Date: Tuesday, June 19, 2012, 9:54 PM 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> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > 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> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120619/99cefb47/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
