Didn't have a clue. I looked them up in an old reference book which list 2 sizes, 6.5x19 and 5x22 15/16.
US Divers Triple 30cu/ft Tanks
- Thread starter Rich Keller
- Start date
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Bob3
Contributor
The 38s I had were the same diameter as a steel 72.
Another real handy, inexpensive, compact bailout was the old "E" steel medical O2 bottles, they hold 25 cu ft & are only 4" in diameter.
Another real handy, inexpensive, compact bailout was the old "E" steel medical O2 bottles, they hold 25 cu ft & are only 4" in diameter.
simonbeans
Contributor
38s with a pressure rating of 1800 psi were 6.9" diameter. As are: 71.2 steel, 42, 50, 63 steel, and Al 50, 45s. All of these cylinders fit nicely in the double bands made by Peanut King. His bands are stainless and better than the originals. A solid bar manifold as pictured above is perfect for your doubles.
These are Al 45s (left) and 50s. Although not considered vintage, they make a good alternative to 38s or 42s. A simple "military style" harness makes this setup very comfortable and usable.
These are Al 45s (left) and 50s. Although not considered vintage, they make a good alternative to 38s or 42s. A simple "military style" harness makes this setup very comfortable and usable.
OP
Rich Keller
Contributor
I did look at the E tanks but they may not be heavy enough. Aluminum scuba tanks are made heavier then they need to be so the tanks will be closer to neutral in the water. Luxfer 19.9cu/ft are 8.09lbs empty, in the water they are +0.12lbs empty and -1.37lbs full. The 27.9cu/ft are 11.4lbs empty, in the water they are +0.6lbs empty and -1.5lbs full. E tanks are 24cu/ft and 7.9lbs empty but I have no in water figures for them. Based on the E tank weight vs its capacity that all ready would be too light and since they are filled to 1900psi the overall tank volume must be greater as well.
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Bob3
Contributor
It's been a while since I used one but they don't float, if that's what you're worried about.
(remember the early US Divers aluminum tanks?)
The butt end was a little light but they're pretty inoffensive to use, way more friendly than many flavors of aluminum bottles.
If ya need something heavy, I do have some squat medical O2 bottles here, some with fairly recent hydros. They're otherwise kinda old & ratty looking but they'd probably be good for another 50 years of abuse.
I'd have to calculate the volume though, they're probably a lot smaller than the Es.
I used to wear tanks about this size sideways just above my butt.
I've been thinking about slapping together some 2-tank "E" rigs to use as bailouts but that won't be 'till summer, when it's "safe" for me to migrate back into Wisconsin where the machine shop is.
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OP
Rich Keller
Contributor
It's been a while since I used one but they don't float, if that's what you're worried about.
(remember the early US Divers aluminum tanks?)
The butt end was a little light but they're pretty inoffensive to use, way more friendly than many flavors of aluminum bottles.
If ya need something heavy, I do have some squat medical O2 bottles here, some with fairly recent hydros. They're otherwise kinda old & ratty looking but they'd probably be good for another 50 years of abuse.
I'd have to calculate the volume though, they're probably a lot smaller than the Es.
I used to wear tanks about this size sideways just above my butt.
I've been thinking about slapping together some 2-tank "E" rigs to use as bailouts but that won't be 'till summer, when it's "safe" for me to migrate back into Wisconsin where the machine shop is.
I was concerned about it being like the early US Divers tanks. I did not do the math but a rough guess had the E tanks at close to 20% more volume then a 19.9 at about the same weight. Then adding to that another 30% due to the fact the 19.9 operates at 3000psi and the E tank operates at 1900psi. I did find a manifold today that should do the job with the dipping tubes about 5 1/2" apart on the center lines. I am not sure how wide a squat E tank is or if it will work with a 3/4" manifold but I would be interested in finding out. I do not care what the tanks look as long as they work. How much were you looking to get for the tanks and how much to ship them?
Bob3
Contributor
The old steel O2 tanks have the 1/2" tapered threads, so that kinda shoots down that idea.
If you managed to dig up a 3/4" manifold you're probably better off going with some new aluminum 30s, or even 40s, they'll fit on that manifold with about enough room to get a bolt between 'em (they're 5.25" diameter)
aluminum bottle specs: XS Scuba Aluminum Scuba Cylinders
If you managed to dig up a 3/4" manifold you're probably better off going with some new aluminum 30s, or even 40s, they'll fit on that manifold with about enough room to get a bolt between 'em (they're 5.25" diameter)
aluminum bottle specs: XS Scuba Aluminum Scuba Cylinders
OP
Rich Keller
Contributor
If I pick this new manifold up I may end up breaking down the three tank set and using them and sell the old manifold on Ebay.
Bob3
Contributor
If I recall correctly, didn't those tanks have the distinction of having been made out of the "crispy" 6351 aluminum alloy?
(Luxfer, made from 1972 through 1st half of 1988)
(Luxfer, made from 1972 through 1st half of 1988)
OP
Rich Keller
Contributor
Yes the tanks are Luxfers all dated 4A87 so they are in that category. The Catalina tanks from the start never had that problem. Just luck of the draw I guess but 50/50 is still better odds then I would get in Vegas. I also see in your profile that you sell commercial equipment. Any idea what a KMB-8 in good condition with a brain bucket is worth?
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