I wonder how long those tanks are certified for. I have a pepsi tank that I rented and filled for another home hobby I used to do. (won't tell you what, not exactly legal). I have the tank in the garage and just bought a two tap keg kit. My problem is the tank has not been refilled in about three years. It still has pressure but I don't know how much. Do you think they will refill it? Maybe exchange it?