UPDATE:
ok its done and it works great with just regular residential gas pressure and nothing special being done to the gas line or gas meter.
here are the videos showing the finished product
part 1 shows the burner
https://www.youtube.com/watch?v=I5otcRH81bE
part 2 shows the burner in action
https://www.youtube.com/watch?v=Shx2UsJc7T0
a few notes -
- an 80 quart pot half full of water takes 25 minutes to reach a regular boil and 5 more minutes (30 minutes total) to reach a rolling boil from cold and I simulated a basket of crabs by dumping in a little over 2 gallons of cold water in and it took 10-12 minutes to return back to a regular boil and 3 minutes longer then that to get back to a rolling boil.
- the time it takes water to boil (as expected) is about double that of my propane burner but its not that big a deal. so what if it takes 15 minutes longer to start boiling when you never have to fool with propane tanks ever again.
- the legs were connected using a standard 1 1/2" long 3/8" bolt with big oversized washer
- the wind guard ring gets very hot (as expected) but the bottom part below the burner ring stays much cooler with only the heat migration causing it to get hot but its not hot enough to burn the powder coat.
- even though it works great just like it is, I plan to ask the gas company to come by and test the gas supply pressure to the house. I figure it wouldn't hurt to be sure to confirm that it is set at the upper range of allowed residential gas pressure to the house.
- those spark ignition things you buy to light burners with wont work, I had one laying around so I tried it and the gas flame is just too low a pressure to light reliably until you have a gas pocket built up and get a big "poof" of flame come out at you, so stick to a regular stick style lighter for lighting the burner.