1950's Navy Tank

[easydiver1]

Does anyone have any of these US GOVERNMENT or USN stamped 38's or similar 38's they would like to part with? Also looking for some steel(not stainless) bands? Thanks

[captain]

Does anyone have any of these US GOVERNMENT or USN stamped 38's or similar 38's they would like to part with? Also looking for some steel(not stainless) bands? Thanks

Not sure why you want them stamped US Government or USN but in any case realize that neither stamp indicates that these tanks are or were actual dive tanks used by the Navy, they weren't. They are tanks originally built and used by the Navy for other purposes and later adapted to scuba by civilians in most cases.
The only true Navy dive tanks were the 90 cu/ft aluminum tanks used by Navy EOD divers.

[easydiver1]

Captain, I realize these were not navy or government dive tanks. My interest is in very early scuba equipment of which many of these gov stamped tanks were used. I guess they were cheap an easy to find. I would like to put together some authentic very early "civilian" dive tanks. I love the look of twin 38's with round bottoms with a military style harness. Had some years ago and wish I had kept them. Thanks for any and all information!

[8dust]

BUSHING GUYS....

Would these work in the neck of my 38's posted earlier in this thread???

They seem a lot shorter than the steel ones so I'm thinkin there is a bunch fewer threads keeping them in place?

[antique diver]

Freddo,
You can believe the rated pressure. This material is way stronger than the cast iron stuff you find in the hardware store plumbing dept. You will have plenty of threads engaged. Don't forget to pick up a roll of Teflon tape if you don't already have it.

One other thing... You might have 1-1/4" NPT threads in the neck of your tank.

[easydiver1]

There are better bushings available. Swagelock and Parker make HP bushing with much longer male threads. With some of these older cylinders, I like as much thread as I need. Bushings should get 2 and 1/2 turns beyond hand tight. These bushings come in carbon steel, brass and SS. I have used the brass ones with no problems other than the cost is much higher with SS bushings over $30.00. Worth it to be safe.

[8dust]

Given the above stampings, what's the rated pressure of these? 1800?

[captain]

Yep 1800, no + rating given to 3A spec tanks.

[kgehring]

I had Qty. 4 3AA 1800 psi tanks that were not good enough to Plus rate. Most of the 2250 psi tanks I have pass the Plus standards.

The 3A steel alloy is not as strong as the 3AA.

[8dust]

Thanks.

It took an hour last night just to get the manifold apart. Will have to post a photo of the thread damage inside one of the compression nuts. It's hard to believe. Can't imagine what someone was doing to get it that way.

Bushings are really froze up. I snapped a strap wrench trying to move them. Put some pen. oil and will strap to something solid tonight and get a bigger wrench.