I use a flex gas line from the tank to my main line on my stand. All my piping on my brew stand is steal gas piping from HD with temp controlled asco valves at each burner (except the boil kettle burner which is manual. I also have a separate ball valve on the MTL and HLT that connect to a small flex copper pipe for pilot lights. I used liquid pipe thread sealant at all joints and haven't had any issues. I did, of course, check for leaks a few times before ever firing it up.