Looks like these are actually twin 42s.
Passed hydro no problem. The guy said they were nice tanks. He was telling me about a tank (not sure what type) from 1902 that came in once and passed. One has a bit of rust inside but nothing that prevented a visual inspection. They will only do a + hydro if the REE is stamped on the tank (by the manufacturer) or can be provided by the manufacturer.
He was kind enough to install the valves for me. Done by machine. Still 3 threads on one and 4 on the other left.
It was funny, they do a lot of tanks for dive shops and mumbled something about most of them having no idea what they are talking about. Especially the 1/2 tapered thread as the NGT thread is used all over the compressed gas industry and SCUBA is a very small percentage of that industry.
He was a bit confused as to why I would want to pull them apart each year to look inside. Little unknown unrelated fact, unlike the CFR in the US Canada has the Transportation of Dangerous Goods Act. The current one in force does require a visually eddy during hydro or even at all on 6351 aluminum tanks. I also confirmed this via e-mail with transport Canada.
Now just to finish the valve rebuild and dive them.
A few questions. This valve is a little bit different that others I have worked on. On the stem of the J and shutoff valve, how does a single teflon washer prevent leaking? I find the stem can be moved up and down when the bonnet is screwed down.
Can I get away with reusing this washer? Should I flip it over as it has a groove worn in it from pushing on the cone on the bonnet.
Does anybody have a Healthways valve the can look at. There is a little spring with a pin on it which holds the J lever up/down. Can someone measure or take a picture so I know what it looks like? Is the end round or flat? I will make on on my lathe as mine is missing. Probably use brass. Not sure where to find a spring that small.
Has anybody tried paintball burst disks in scuba valves? They make single piece that will let go at 3000 PSI. Just wondering if they are long enough.
Does anybody have any recommendations on what to use between the bands and the tank that would look half decent. Without them the bands seem a bit loose when tightened. The original plastic liners is starting to crack probably not original to the tank). The had a bit of a lip that came over the edges of the band.