Rich's Bushing Mystery
- My buddy Rich bought a like-new steel USD 72 Tank at a garage sale. It's kind of a mystery because it is a 1964 scuba diving tank (not war surplus) that has a bushing with the 1/2" tapered thread J-Valve. Unlike other bushings, it is screwed in flush with the top of the tank. The tank neck diameter is identical to earlier USD tanks from 1961 that are threaded for the 3/4" O-Ring valves.
- At first we were thinking maybe the bushing is not a tapered thread but rather an adaptor that fits the standard 3/4" O-Ring tank necks. But when we tried to unscrew it, it is in there SOLID. It has damage from a previous (not us) use of a pipe wrench that looks like it might not have been successful... The paint looks like the bushing didn't come off. This was probably for the 5 year hydrotest that was done in 1971. And we're thinking the hydrotester just removed the valve and left the bushing in for the test?
- The insides are bare steel that is pristine except for flash rust from the hydrotest. It's a very nice tank.
- We're wondering a few of things:
1. Can we get a hydrotest with the bushing installed on the tank?
2. Is it a tapered thread bushing or a 3/4" O-Ring adaptor bushing?
3. Any suggestions for how to get it off without damaging it or the tank.?