I have learned that, contrary to what they tell you, the big box stores will not connect your gas dryer when they deliver it. So I was left to do it myself.
The guy told me to remove the incorrect sized inlet flange fitting on the wall pipe and replace it with a coupler. The one I bought did not fit on one side.
But the flange that came with dryer fit the bare pipe threads so I installed it, used some goop, leaked tested with soapy water and ran the dryer and it works. I circled my work in purple.
But is this the correct way to install a gas fitting???
EDIT2: The inside of the steel fitting and the outside of the cast iron pipe are both threaded.