Right and that is accounted for. I can flow both hydrant and sprinks simultaneously for the total duration of each. I may or may not need a pumper at the hydrant. This is actually more of a pressure question and is just theoretical. If the hose stream portion of the sprinkler demand crosses the the supply curve from the pump so I don't have the required flow at with the hose stream but there is more on-site water than I need to flow both (and that is not subject to demand fluctuations from other users) I can adjust my pump curve. The question though is why should I need to add that demand on the sprinkler calc where the supply to the sprinks and the supply to the hydrant diverge? This is akin to doing a rack calc and an overhead calc and then adding an arbitrary extra amount of gpm at the common point of divergence from the main after you've balanced the two. There's no problem to overcome since in the actual case the hose demand can be added without causing the problem but it did bring up the question of why does it need inclusion in the first place under these conditions. The obvious parent answer is because I (the code) say. All the exceptions are for process water and when there are only sprinklers on the tank. If I had a small elevated tank for the sprinks only and another for the hydrant only I wouldn't have to include hose stream but when I combine the both in the same tank I do. Doesn't make sense to me.
On Wed, Jun 29, 2011 at 12:32 PM, <[email protected]> wrote: > That section is when there are no hose valves or hydrants on the water > supply from the tank. When there is no means to utilize hoses there is no > need to account for the Hose Stream allowance in the calcs. > > This section does not apply to systems where the fire water storage tank > supplies a loop where there are either hydrants or buildings with hose > connections. > > If I remember correctly, if your building has hose connections internally, > you add the interior hose demand at the base of the riser and the remainder > at the point of connection to the existing UG supply. If you only have yard > hydrants and no internal hose connects you add the total hose stream demand > at the point of connection to the existing UG supply. > > Remember that sprinklers are for control, not necessarily for > extinguishment so there could be sprinklers flowing and hose line attack > occurring at the same time. > > 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 Jarron Gass > Sent: Wednesday, June 29, 2011 3:26 PM > To: [email protected] > Subject: RE: Hose Stream > > NFPA13, 2010 edition > 11.1.6 Hose Allowance. > 11.1.6.1 An allowance for inside and outside hose shall not be > required where tanks supply sprinklers only. > > Jarron J. Gass - J. & J. Fire Protection Co., Inc. > 101 Powell Rd., Butler, PA 16002, > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Todd > Williams > Sent: Wednesday, June 29, 2011 3:15 PM > To: [email protected] > Subject: Re: Hose Stream > > Perhaps those in the fire service could answer this better, but I'll give > my > thought. My take is that our designs are to provide sprinkler protection > plus one or two hose streams to a fire prior to the fire department > augmenting the water supply (except for systems with pumps that equal or > exceed the pumps in their trucks) If that is the case, the hose stream > calculation needs to be included. If the pump is large, the hose streams > would be needed as part of the overall fire protection plan. So yes, you > have to include them. > > > At 02:53 PM 6/29/2011, you wrote: > >Back to an old question but a little different. Tank with sufficient > >capacity to supply duration for both a yard hydrant and the sprinkler > >system. Pump sufficient to supply required psi to the sprinks and meet > >the AHJ's requirement at the hydrant. Question: When calculating the > >sprinks do I need to add the 250 gpm hose allowance on that demand > >curve? This seems to be a 'safety cushion" for a water supply > >controlled by an outside party such as a municipality. This is not the > >case here wherein the quantity of water and delivery pressures are > >completely controlled: a closed versus open system if you will. > > > >-- > >Ron Greenman > >Instructor > >Fire Protection Engineering Technology > >Bates Technical College > >1101 So. Yakima Ave. > >Tacoma, WA 98405 > > > >[email protected] > > > >http://www.bates.ctc.edu/fireprotection/ > > > >253.680.7346 > >253.576.9700 (cell) > > > >Member: > >ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC > > > >They are happy men whose natures sort with their vocations. -Francis > >Bacon, essayist, philosopher, and statesman (1561-1626) > >_______________________________________________ > >Sprinklerforum mailing list > >[email protected] > >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > > >For Technical Assistance, send an email to: [email protected] > > > >To Unsubscribe, send an email > >to:[email protected] > >(Put the word unsubscribe in the subject field) > > Todd G. Williams, PE > Fire Protection Design/Consulting > Stonington, CT > 860.535.2080 > www.fpdc.com > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
