halocline
Contributor
You guys are technically correct from a U.S. perspective. To the best of my knowledge, no steel 2250 psi cylinder in Canada can be given a "+" rating on a subsequent hydrostatic inspection. In the U.S. this was not usually done as most testing facilities would not test or be capable of testing to the standard required (see NOAA dive manual).
I'm almost certain you're wrong on this. The plus rating testing requires no additional test over the standard hydro test, it just requires having the correct REE number to know what the acceptable expansion is. I've been told by several hydrotesters that 3AA2250 tanks rarely fail the plus rating test, probably because the service pressure is conservative relative to other scuba tanks. The primary reason so many (including mine!) 72s don't have a current plus rating is because the tester does not have access to the REE number or is simply too ignorant and/or lazy to include the rating. Sometime after the debacle with my tanks, I found a friend's faber LP80 with this same tester's mark. The tank did not have a plus rating, the REE number is clearly stamped on the tank, and the guy did not stamp "no plus" as he idiotically did on mine.