I can't help you find the link but I can tell you a few things about my natural gas hook up.
From the point of entry or where you tap into the gas line you will need to run
1/2" black pipe to a close to your torch bench. I sure local codes will cover that and where shut off valves are. The problem has always been converting from natural gas piping sizes to welding fittings. Places like Home Depot have the stuff but the staff may not know it.
I would take your welding hose to a welder supply or Home Depot/Lowle and show and say fit this to a 1/2 black gas pipe.
I have a flame arrestor in my fuel ( Natural gas line ) where the welding hose connect to the gas line. I don't know it it code but it sure is a good idea. Carlyle
the maker of your CC have them
http://www.carlislemachine.com/Carli...FireChecks.htm
I hope that helps
Gordon