To identify what it is without a pic, what is the valve hanging off does it have a solid pipe covered in black plastic coming from/into it or does it just have a black/red/blue plastic pipe ????? or clear plastic.........................................a pic would be great.
If it's gas you will find a couple of others around the place.
We have a 14.44-5, need a pic as there are a couple of valves underneath. Gas seems the most probable. Can you trace where it is going? If it is on a Cu line, definitely gas.