I would use extreme caution anytime you add PRV's to an existing system. If you really look at them, lowering the static pressure is only the beginning of your work as your residual pressure per floor could be reduced dramatically. As I have learned more and more about PRV's I have been very surprised at what a negative impact they can have on the calcs....
Greg On Thu, Aug 25, 2011 at 6:27 PM, Ben Young <[email protected]>wrote: > So I guess a variable speed controller would be out of the question, even > when compared to the lifetime cost of the additional inspections of all > those PRVs? > > Benjamin Young > > > > On Thu, Aug 25, 2011 at 12:07 PM, <[email protected]> wrote: > > > Ken, sounds very similar to our situation. Biggest hurdle is that our > > client is exceptionally fearful of anything new. This is all new > territory > > for them. > > > > Craig L. Prahl, CET > > Fire Protection > > CH2MHILL > > Lockwood Greene > > 1500 International Drive > > Spartanburg, SC 29304-0491 > > Direct - 864.599.4102 > > Fax - 864.599.8439 > > CH2MHILL Extension 74102 > > [email protected] > > > > > > > > -----Original Message----- > > From: [email protected] [mailto: > > [email protected]] On Behalf Of Travis Mack, SET > > Sent: Thursday, August 25, 2011 11:49 AM > > To: [email protected]; [email protected] > > Subject: Re: Pressure reducing valves on system risers > > > > Craig: > > > > We ran into something similar on a building expansion recently. There > > were 4 existing systems and we were adding a new system. The building > > had an existing fire pump. Apparently, the city supply was upgraded > > significantly, as we had the original flow test from the original > > drawings. We discussed it with the owner, and they decided to put a > > pressure reducing valve on each riser, instead of on the manifold. We > > knew the base of riser demands from the riser stickers. So, the > > installing contractor just set the PRV's at about 10 psi above the base > > of riser pressures. If I recall correctly, BOR pressure was about 150 > > psi so they set the PRV at 160. > > > > What amazed me about this, is that after some investigation of prior > > pump test reports, it was found that the pump discharge pressure had > > been above 200 psi for about 5 years. The inspection company never > > mentioned that this might be an issue. > > > > On 8/25/2011 8:41 AM, ParsleyConsulting wrote: > > > Jim, > > > Maybe I missed the intro to what Craig was asking about, but I had the > > > impression that these systems were existing. That would make it very > > > difficult if not impossible to replace the sprinklers and fittings > > > with higher rated devices. > > > > > > Craig? Existing or new? > > > > > > PARSLEY CONSULTING > > > > > > Ken Wagoner, SET > > > > > > 760.745.6181 voice > > > > > > 760.745.0537 fax > > > > > > [email protected] <mailto:[email protected]>e-mail > > > > > > www.ParsleyConsulting.com <http://www.ParsleyConsulting.com>website > > > > > > > > > > > > On 8/25/2011 8:35 AM, Jim Davidson wrote: > > >> Why not use 250 psi rated high pressure sprinklers and use 300 psi > > >> rated fittings, pipe and pipe joining devices such as Vic Grooved > > >> product and 300 psi rated ductile threaded fittings. These products > > >> were developed to reduce the number of PRVs in high rise buildings. > > >> There should be no problem with using 250 psi rated sprinkler heads > > >> and 300 psi rated pipe and fittings. You just need to check the > > >> rating with the manufacturer's working pressure. > > >> > > >> Have a fire safe day. > > >> > > >> Jim Davidson > > >> Davidson Associates > > >> Fire Protection * Medical Gas * Code Consulting 302-994-9500 > > >> Fax:302-234-1781 > > >> > > >> > > >> -----Original Message----- > > >> From: [email protected] > > >> [mailto:[email protected]] On Behalf Of > > >> [email protected] > > >> Sent: Thursday, August 25, 2011 9:46 AM > > >> To: [email protected]; [email protected] > > >> Subject: RE: Pressure reducing valves on system risers > > >> > > >> I've already been told, no changes to the pumping systems or their > > >> settings. > > >> > > >> The idea of a large one with a smaller on a bypass may be the way to > > >> go but I have to wait to see if the owner wants one on the run-in or > > >> one on each system riser off the manifold. > > >> > > >> Craig L. Prahl, CET > > >> Fire Protection > > >> CH2MHILL > > >> Lockwood Greene > > >> 1500 International Drive > > >> Spartanburg, SC 29304-0491 > > >> Direct - 864.599.4102 > > >> Fax - 864.599.8439 > > >> CH2MHILL Extension 74102 > > >> [email protected] > > >> > > >> > > >> > > >> -----Original Message----- > > >> From: [email protected] > > >> [mailto:[email protected]] On Behalf Of Joe > > >> Sent: Thursday, August 25, 2011 8:58 AM > > >> To: [email protected] > > >> Subject: Re: Pressure reducing valves on system risers > > >> > > >> Also what is the highest demand sprinkler or standpipe system ? Is > > >> pump is overdesign see if modification to fire pump be done I.e. > > >> Change impeller > > >> Sent on the Sprint® Now Network from my BlackBerry® > > >> > > >> -----Original Message----- > > >> From: "Morey, Mike"<[email protected]> > > >> Sender: [email protected]: Thu, 25 Aug > > >> 2011 08:44:07 > > >> To:<[email protected]> > > >> Reply-To: [email protected] > > >> Subject: RE: Pressure reducing valves on system risers > > >> > > >> Can you provide a pair of PRVs at each manifold? Typically we'd look > > >> at a large valve (say 6 or 8") with a bypass through a smaller valve > > >> (maybe a 3"). Large PRVs have a minimum flow rate much higher than > > >> one sprinkler would flow so the smaller PRV allows for low flows like > > >> those that would be found when a single sprinkler activates. > > >> > > >> Mike Morey, SET, CFPS > > >> Sprinkler Designer > > >> BMW Constructors, Inc. > > >> O: 317.651.0596 | C: 317.439.2695 > > >> www.bmwc.com > > >> > > >> ________________________________ > > >> > > >> From: [email protected] on behalf of > > >> [email protected] > > >> Sent: Thu 8/25/2011 8:32 AM > > >> To: [email protected] > > >> Subject: RE: Pressure reducing valves on system risers > > >> > > >> > > >> > > >> Ah there's the rub. This is a multi-building manufacturing site. > > >> HUGE! A mixture of very large buildings and some not so large, > > >> multi-story and single story. But a single story could be 50 ft > > >> high. The problem is that the pump is overdesigned. Not sure if > > >> the municipal supply changed or just a bad pump selection. Either > > >> way doesn't matter. Already been told that they will not make any > > >> changes to the pumps. So, any corrective action will be provided at > > >> the risers. > > >> > > >> They have a standard that dictates that buildings be zoned and that > > >> each zone is served by a separate riser. Case in point, a new > > >> 2-story, 60 ft high, 60,000 total sq. ft. building has 8 system > > >> risers fed off two manifolds, one at each end of the 300ft long > > >> building. I can't do combination standpipe risers either. > > >> > > >> Welcome to my world................. > > >> > > >> Craig P > > >> > > >> > > >> > > >> -----Original Message----- > > >> From: [email protected] > > >> [mailto:[email protected]] On Behalf Of Matt > > >> Grise > > >> Sent: Thursday, August 25, 2011 8:25 AM > > >> To: '[email protected]' > > >> Subject: RE: Pressure reducing valves on system risers > > >> > > >> What is the building like? (are there upper floors that wont need > > >> PRV's?) what is the water supply like? > > >> > > >> Matt Grisé PE*, LEED AP > > >> Sales Engineer > > >> Alliance Fire Protection > > >> 130 w 9th Ave. > > >> North Kansas City, MO 64116 > > >> > > >> *Licensed in KS& MO > > >> > > >> 913.888.0647 ph > > >> 913.888.0618 f > > >> 913.927.0222 cell > > >> www. AFPsprink.com > > >> > > >> > > >> -----Original Message----- > > >> From: [email protected] > > >> [mailto:[email protected]] On Behalf Of > > >> [email protected] > > >> Sent: Thursday, August 25, 2011 7:21 AM > > >> To: [email protected] > > >> Subject: Pressure reducing valves on system risers > > >> > > >> Got a major client whose system was poorly designed. They have their > > >> jockey pump set for about 200 psi and their main fire pump is putting > > >> out 180-190 psi. The local fire marshal has mandated that they > > >> provide pressure reducing valves on the system risers for all new > > >> systems. Anyone ever done this? Any recommendations? > > >> > > >> Forget about doing the logical thing and looking at the pump, there > > >> is very little common sense here and the process of change is long > > >> and painful. > > >> > > >> Craig P > > >> > > >> > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> > > >> > > >> -------------- next part -------------- > > >> A non-text attachment was scrubbed... > > >> Name: winmail.dat > > >> Type: application/ms-tnef > > >> Size: 6030 bytes > > >> Desc: not available > > >> URL:< > > > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20110825/5d49a3fd/attachment.bin > > > > > >> > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> > > >> > > >> _______________________________________________ > > >> Sprinklerforum mailing list > > >> [email protected] > > >> http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > >> > > >> > > > _______________________________________________ > > > Sprinklerforum mailing list > > > [email protected] > > > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > > 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/20110825/ccb3a32a/attachment.html > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -- Greg McGahan Living Water Fire Protection, LLC <http://www.livingwaterfp.com> 1160 McKenzie Road Cantonment, FL 32533 850-937-1850 fax 850-937-1852 -------------- next part -------------- An HTML attachment was scrubbed... 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