You learn something new every day. Prior to last Tuesday, I had no idea that there was such a thing as a DOT licensing exemption. I also didn’t know that I cared.
Turns out that some scuba tanks are manufactured under special exemptions granted by the DOT that allow for special sizes, pressure ratings, or whatever. An example is the Sherwood Genesis and others stamped E9791. I think these were made by Pressed Steel Corp.
Here’s the thing. Those exemptions need to be renewed. If they’re not, once the exemption runs out, it becomes illegal to fill the tank. It doesn’t matter that it has been inspected annually, or flies through a hydro, the cylinder is as good as condemned.
I own three such cylinders and LOVE them, yet they are scheduled to lose their exemption next year and all will be useless unless some arrangement can be reached with the DOT.
It’s bad enough that they cost a lot, but what really sucks is that they are about as perfect (to me anyway) as a scuba tank can be. Replacement with a similar (but less perfect in my opinion) set will be over a grand. Yet all three are perfectly safe without a speck of rust and currently within hydro.
[UPDATE: April 12, 2017] https://www.divenewswire.com/urgent-industry-update-psi-pci-sp9791-cylinder-permit-status/