If you're going to chain one to the actual valve itself PLEASE consider getting a one-way tool. There is a patent out there for one, but I could not easily find one (if you know someone with a torch, you can probably fix this easily). It appears there are also values that will make a 1/4 turn to off, and then require a special tool to open them. These would help prevent someone trying to be "helpful" from turning on your gas supply before it is properly inspected and for pilot lights to be properly lit.