Sorry if this is the wrong place for this. I need to run iron pipe to a stove. There will have to be some corners to go around basement stairs. I read somewhere that you can't use unions for natural gas but have to use left/right couplers. I know it would be a real pain if I did not use anything and had a leak but if I make sure everything is tight would there be a problem. I guess what I am asking is it code that you have to use left/right or is it just for insurance? Thanks