In Reply to: Re: Re: Re: Re: US Divers Steel 72 Tank Valve Leak (1958) posted by B. Xavier on November 20, 2012 at 17:43:35:

!/2 valves use a tapered thread, every time you have the valve off the tank, it takes a little bit more of a turn to get it to seal, and eventually you will run out of thread. A fix you can do (once) is to mill off a little bit of length on the tank neck which will allow you to turn the valve a little farther into to taper of the tank threads.