I am expanding my deck and want to move my gas grill to the other side. The current setup has a galvinized line coming out, a valve, then a flex line to the grill. I am going to remove all this, as it will be in the way (it won’t work where I plan to reinstall the line) and want to place flex all the way out. Can I use flex lines with couplers the entire run, if I make sure they are gas tight?