Old Steel Tank

[Kland84]

That's an oxygen valve which we used back in the 50's for diving.

I was born in 1984, been diving since 2001. Never seen a valve like this. I actually had to search the net to figure out what it was.

 

[Scared Silly]

The cylinder is an old PST born 4-61. Get it re-qualed and buy a new valve: XS Scuba PRO 1/2" NPT Threads

 

[Bob DBF]

The cylinder is an old PST born 4-61. Get is re-qualed and buy a new valve: XS Scuba PRO 1/2" NPT Threads

I still use the old post that came on my old steel 72. The valve as handle problem is solved if you can find a j-valve version of the post valve, I've only seen one in pictures, and I've been around a while.


Bob

 

[Stoo]

I still use the old post that came on my old steel 72. The valve as handle problem is solved if you can find a j-valve version of the post valve, I've only seen one in pictures, and I've been around a while

J-valves were pretty common up here, but nobody really used them for what they were designed to do. In fact, most people I knew had removed the j-rod because in theory, they could be pulled by accident, and so your reserve was gone. Mind you, by the time I started diving in '74, most of us were using SPGs by then, so the "reserve" function had become less of a "thing".

J-valves impeded breathing performance a little too. When the valve was set to hold back a reserve, most regs would get harder to breath at around the 5-600 psi mark and continue that down towards 300 psi when you had to pull the reserve. If you weren't using a SPG, and the reserve had been accidentally pulled, your first clue that you were getting low on air was when you were low on air... Ya know, like 6 breaths before you were out of air. We called those "character builders".

 

[Bob DBF]

J-valves were pretty common up here, but nobody really used them for what they were designed to do

I've got a couple of j-valves on the tanks I use with my old double hose, one of the new '80's version I use on an LP 95 boat tank, and one from the '60's on a similar vintage old steel 72. What I was referring to was a post valve with a j-valve mechanism.

http://vintagescuba.proboards.com/thread/3754/jerrys-green-tank
The link to a page with a picture, best I can do with with the pos iPad I'm using.


Cheers

Bob

 

[RayfromTX]

I have an oxygen tank stamped 1952 and a helium tank stamped 1963. They have been hydroed every 10+- years since. Steel is real.

 

[Eric Sedletzky]

I got freebie 72’s with 1/2” NPT tapered threads. One was 1959 and the other 1960. Both were great tanks. One thing that might doom that valve is that the burst discs were of the type that had the hole in the center of the nut aimed straight out. If the burst disc ever blew a chunk could fly out and hurt someone. So they went to the side vented style. Those end hole style are illegal now and nobody will fill a tank with such a bust disc nut. The problem is, I’ve never been successful at removing an old nut without twisting it off. Every single one of them was corroded in and virtually “welded” into the valve. I’ve tried everything to try and surgically remove an old nut without screwing up the valve (FUBAR), but I’ll never been able to save one. Luckily I’ve found later model tapered thread J-Valves and swapped them out.
The other problem with the narrow neck is I can’t get a whip or cleaning tools in the tank to scrub them. They have to be tumbled or blasted to get any rust out. I ended up selling off all my 1/2” neck tanks and hung onto my 3/4” 72’s instead.
I have 5 - 72’s now and that’s plenty for me.

 

[dead dog]

The cylinder is an old PST born 4-61. Get it re-qualed and buy a new valve: XS Scuba PRO 1/2" NPT Threads

The tank shown has a 1/2” NPT tapered threads and I don't think the Scuba-Pro vale with straight threads would fit.

 

[Bob DBF]

The tank shown has a 1/2” NPT tapered threads and I don't think the Scuba-Pro vale with straight threads would fit.

The valve shown looks like straight threads, but is labeled as NPT which is a tapered thread. The 3/4 and 1/2 straight threads are NPS. Although I have an old 1/2 NPS valve in my dive locker, I have never run across a tank that would fit it, as it was a short term interim before the 3/4 straight.


Bob

 

[Scared Silly]

The tank shown has a 1/2” NPT tapered threads and I don't think the Scuba-Pro vale with straight threads would fit.

Look (and read) carefully the valve threads are tapered.