FDC does not have to be 4". It can be smaller. We see this a lot with apartments designed to nfpa 13. A 2" supply can often feed sprinklers with the right conditions.
I have run into cases where the civil has sized the underground too small. I just send the info from NFPA 13 & 24 that says minimum 6" unless hydraulically calculated. I ask them to provide calculations if the UG size is causing us problems. If no calculations then we state either it has to be a 6" pipe or a change order for increased interior piping due to improperly sized supply lines. Travis Mack, SET MFP Design, LLC "Follow" us on Facebook: https://www.facebook.com/pages/MFP-Design-LLC/92218417692 Send large files to MFP Design via: https://www.hightail.com/u/MFPDesign Sent from my iPhone > On Dec 3, 2014, at 8:19 AM, Brian Harris <[email protected]> wrote: > > Todd- > What's your take on the FDC coming off the Riser & the 2" underground? > > Brian Harris, CET > BVS Systems Inc. > bvssytemsinc.com > > > -----Original Message----- > From: Sprinklerforum [mailto:[email protected]] > On Behalf Of Todd - Work > Sent: Wednesday, December 03, 2014 9:58 AM > To: [email protected] > Subject: Re: Riser Size > > I have always sized them by hydraulic calculation (or pipe schedule). No > minimums. > > Todd G Williams, PE > Fire Protection Design/Consulting > Stonington, CT > www.fpdc.com > 860-535-2080 (ofc) > >> On Dec 3, 2014, at 9:43 AM, Brian Harris <[email protected]> wrote: >> >> I can't seem to put my finger on it this morning but is there a minimum size >> requirement for the Riser in a 13 system? I know there is for the FDC >> connection and the underground main to the building but I don't see anything >> the limits the size of the Riser except the hydraulic calculations. In this >> particular job the FDC is located on the Riser so I assume the Riser would >> at least have to be 4" up to the FDC connection. Currently the civil drawing >> is show a 2" supply to the building from a 6" underground main.... >> >> Brian Harris, CET >> BVS Systems Inc. >> Sprinkler Division >> bvssystemsinc.com<http://bvssystemsinc.com/> >> Phone: 704.896.9989 >> Fax: 704.896.1935 >> >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
