You simply can't get the old style tanks filled in the
USA, but you probably can in many places outside of the
USA. Luckily, the new style valve also takes the old style fill connector. Some
parts of the world have completely different connectors and will require an adaptor, but throughout most of the
Caribbean you can get tanks filled at reasonable intervals. I investigated getting the valves changed when the law changed and it was more expensive than getting new tanks, so I bought new tanks.