The POC would be where the dry pipe valve connects to the wet system (the assumption is that it does not have an express main). That way the dry pipe pipe is calc’ed with 4 sprinklers but the system is able to deliver water to a bigger fire (aka - one at the boundary between the two).
Roland Huggins, PE - Senior VP Engineering American Fire Sprinkler Assn. Dallas, TX http://www.firesprinkler.org <http://www.firesprinkler.org/> Fire Sprinklers Saves Lives > On Mar 14, 2017, at 12:25 PM, Ed Kramer <[email protected]> wrote: > > Maybe I’m not understanding section 23.4.4.2.5 properly. Hypothetical > situation: small loading dock protected by 4 sprinks on an auxiliary dry > system. Calculated demand of the 4 sprinks is 104 gpm. Based on the 104 > gpm, the pipe that connects the dry valve to the wet system, the dry pipe > valve, and the dry system cross-main can all be 2”. But 23.4.4.2.5 says to > add 286 gpm [(.20 x 1950)- 104] at the point the last BL connects to the dry > main. Now I’ve got 390 gpm flowing through the pipe that connects the dry > valve to the wet system, the dry pipe valve, and the dry system cross-main. > And they just all increased in size from 2” to 4”. And they all feed just 4 > sprinklers. What am I missing? > > Ed Kramer > Bamford Fire Sprinkler > > From: Sprinklerforum [mailto:[email protected]] > On Behalf Of Roland Huggins > Sent: Tuesday, March 14, 2017 12:52 PM > To: [email protected] > Subject: Re: NFPA-13 (2016) > > This very sensible approach was added to address smaller remote areas > (loading docks, precautions systems, small areas of higher hazard > classifications etc). Historically we were suppose to pick up additional > floor area by adding sprinklers from the adjacent area. That was typically > ignored fro small preaction systems and went both ways for loading docks. > The loading dock brought it to a head since it is typically spray sprinklers > and the warehouse is often ESFR. > > AS as interesting tidbit, this approach does NOT require you to include the > overage in flow we typically have to include in all other calculations. > > Roland > > > Roland Huggins, PE - Senior VP Engineering > American Fire Sprinkler Assn. > Dallas, TX > http://www.firesprinkler.org <http://www.firesprinkler.org/> > > Fire Sprinklers Saves Lives > > > > >> On Mar 14, 2017, at 5:56 AM, Brian Harris <[email protected] >> <mailto:[email protected]>> wrote: >> >> I’ve had an engineer reference sections from NFPA-13 (2016) of which I do >> not have a copy. If anybody has it could you please tell me what these two >> sections say? >> >> NFPA 13 2016 23.4.4.2.4 and 23.4.4.2.5 >> >> Thanks in advance. >> >> Brian Harris, CET >> BVS Systems Inc. >> Design Manager >> bvssystemsinc.com <http://bvssystemsinc.com/> >> Phone: 704.896.9989 >> Fax: 704.896.1935 >> >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> <mailto:[email protected]> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> <http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org> > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > <mailto:[email protected]> > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > <http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org>
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