old gas valve

HI, I am replacing a gas dryer with an electric dryer. The gas valve on the gas line doesnt look like any I've ever seen at the hardware stores. I assume it is because it is so old. It looks like a rectangular tab over a round disk that fits on top of a brass fitting. It has a hole in the middle of it. (maybe to use a screwdriver to turn it) When I turn it, it rotates 360 degrees and just keeps turning endlessly. It doesn't appear to start comming out of the brass fitting pipe. Is this a valve that you turn perpendicular to the pipe to shut off and turn parrallel to the pipe to turn on? Or is it even a valve at all?

valve

It is hard to say from your description, but since it would not be AGA approved throw it away and install a new gas valve. It probably leaks anyway.