thanks Lamplighter for your concern. respectfully, I've found little good information from ehow.com. Even though that link says there could be leaks at the seams, another "black pipe" link on that very page says black pipe is preferred for gas because of its seamless construction. ehow just isn't very consistent or reliable in my experience.
For a project like this, I had two main research goals: one, to figure out how to do the project and two, to figure out what sources of information were reliable. I wind up doing both simultaneously. As I learn more about the how and why of the job, I can better judge the quality of the source of information. I consult lots of websites, my friends, clerks/salespeople in stores, not to mention my own eyes. In my basement, the gas comes into the house via iron pipe, for example.
I *did* read the article at your link, and a handful of others spawned from that link, so, thank you. Not all of ehow.com is junk, it just seems like it's been gathered and collated by a robot from aaaalll over the place.
Thanks again friends.