For a dry system using galvanized piping in nfpa 2007 13 edition is it required to have 120 or 100 c-factor? Also is there anything in nfpa 2010 that also requires the use of 100 c-factor for galvanized piping?
2013 edition changed galvanized to C100. 2010 and older allows you to use C120 for galvanized. That doesn't mean you can't use 100 or something less for whatever reason.