JBarn

Hello everyone! I just started building my first forced air ribbon burner forge that will be ran on residential natural gas. My question is what is the best way to set up the gas orifice? I've looked around on here for an answer but can't find it yet. I'm running 2" pipe so I know the orifice has to be 18" from the burner but would it be ok for the orifice to be 26 inches away and what is the minimum size for a gas supply line I can run? Thank you!