So I have the total demand at the BOR and the expected pressure loss from static with the entire design area flowing. How does a main drain test simulate this? My understanding of the main drain test is a comparative analysis of pressure drop as recorded at acceptance from the Contractor's Above Ground Materials and Test Certificate with the pressure drop at the time of the test. I presume that original data is what is noted under the area of the placard for "Supply Data" and is irrelevant regarding the calculations.
On Fri, Jul 8, 2016 at 10:16 AM, Steve Leyton <[email protected]> wrote: > The information of value at least once a year when you do the main drain > test. Maybe you could add both BOR and Source demands, but I don’t agree > with posting Source data in lieu of BOR. > > > > SL > > > > *From:* Sprinklerforum [mailto: > [email protected]] *On Behalf Of *Todd > Williams > *Sent:* Friday, July 08, 2016 10:15 AM > *To:* [email protected] > *Subject:* RE: Base of riser on placards > > > > I'll ask the unthinkable question, is the BoR demand on the placard > worthwhile? Hydraulic calculations are done back to the effective point of > the flow test. The underground losses, hose demand and sometimes backflow > preventer losses are taken before the BoR. Consequently you cannot compare > the BoR demand to a new public water test and make a valid conclusion > without a full set of original plans and calculations. Wouldn't it make > more sense to put the demand at the water source on the placard? > > Todd G Williams, PE > > Fire Protection Design/Consulting > > Stonington, CT > > 860-535-2080 (ofc) > > 860-608-4559 (cell) > > > > Sent using CloudMagic > <https://cloudmagic.com/k/d/mailapp?ct=ti&cv=6.0.64&pv=8.2> > > > > On Fri, Jul 8, 2016 at 10:21 AM, Ed Kramer <[email protected]> wrote: > > I’ve asked this question in the past and the answers have been all over > the board. > > > > I tend to think the BOR location needs to be consistent from project to > project, whether it’s a single system riser or multiple system risers. In > our part of the universe, most (but not all) backflow preventers are > located inside the building immediately downstream of the underground > flange. I locate the BOR at the underground flange on all systems. By > placing data from that location on the Hydraulic Design Placard, it makes > it easier for someone else to compare the sprinkler system demand to water > supply data. > > > > I believe the intent is to include the combined hose allowance, but got > nothing from the standard to back that up. With a strong water supply (lots > of volume), available pressure while flowing the sprinkler plus hose demand > is going to be virtually the same as pressure available while flowing only > sprinkler demand. But many of the water supplies we work with are marginal. > Removing 100, 250 or 500 gpm combined hose allowance from the water supply > can make a very significant difference in available pressure. So when > comparing sprinkler demand to water supply data, knowing the combined hose > allowance is very helpful. > > > > Respectfully, > > Ed Kramer > > Bamford Fire Sprinkler > > > > > > > > *From:* Sprinklerforum [ > mailto:[email protected] > <[email protected]>] *On Behalf Of *Ben Young > *Sent:* Thursday, July 07, 2016 3:06 PM > *To:* [email protected] > *Subject:* Base of riser on placards > > > > What's the general consensus on the location of the 'base of riser' for > hydraulic placards that everyone uses? See Figure A 24.5 in the 2010 > Edition of 13 and/or 24.5.2 > > I feel its supposed to be at the base of each sprinkler riser (where you > have multiple systems) where it ties into a common header. > > Others in my office think its where the incoming flange comes into the > riser room. > > If you have a vertical riser with a vertical backflow, then these two > points would be the same with either method in my line of thinking. > > Also, is the hose indicated on the placards supposed to be inside hose > only, or combined in and out? I just realized after reading this today > that it could only be referring to inside hose, but I've always put the > combined hose there... > > Thanks, > > > Benjamin Young > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > -- Ron Greenman 4110 Olson Dr., NW Gig Harbor, WA 98335 [email protected] 253.576.9700 A problem well stated is a problem half solved. -Charles F. Kettering, inventor and engineer (1876-1958)
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