Lube for gas shut off valve

[Gold Digger]

Does anyone know of a lube for shut off valves? The valves on two of my "A's" are real hard to turn and one is a new one. Also I'm having trouble with a tapered plug valve on a "B" John Deere. I was wondering if I rubbed some kind of soap on them if it would stay on them and not cause troubles else where. I know soap will work in an emergence when you knock a hole in a gas tank and gas don't break it down. Maybe someone knows of something made just for the business.