I have a weird problem with a 10 lb NOS brand tank. Every time I put it in a freezer to chill it, it will completely leaks out. For example I have 5 lbs in it, and put it in the freezer overnight so I can top it off easily on the refill, well in the morning it will be completely empty. I am wondering if the blow off disc warps slightly when it gets down to a low temperature. I have made sure the valve is closed and it has no leaks. It can sit all winter in room temperature and will not leak at all. It is the stubby hi-flow NOS tank.