Can someone tell me what this is?

[oxyhacker]

Ok, here's the story. Catalina apparently has been making these tanks for the Australian market. They had a bunch of extras, so they sold them to Cramer Decker, the Sherwood and Genesis distributor, who is distributing them here. They were apparently made to meet DOT specs, so Catalina was able to stamp them with DOT markings, hence your low number.

Whether they are just going to be selling off this one batch, or will become a standard item depends on how what kind of reception they get on the US market. An oddball tank, to be sure, though since it is a 3AL rather than an exemption, you don't have to worry about an exemption expiring if C-D loses interest in them.

 

[pescador775]

Sorry, I don't understand what you mean. Most tanks with a 3442 pressure rating are steel (3AA).

"3AA" is a chrome molybdenum steel (ASTM 4130). Domestically sold steel tanks rated 3442 psi are not 3AA steel, they are carbon/chrome/ manganese/silicon steel (I believe) approved for sale under E9791 permit. Faber has sold some DOT3AA, 3180+ psi tanks in the USA but never a 3442 psi. In Australia, Faber is selling light weight, 3300 psi steel tanks with 7.0 diameter and various capacities. They could be high tensile steel or rebadged LP tanks made from 3AA. However, the test criteria are similar to E9791 (3/2 WP). I would like to know, myself, for purposes of continuing education.

 

[jsado]

Wow thanks for all of the responses! If you guys want some pics I'd be glad to post them.... next post in a little bit

 

[jsado]

Here are the pics... the 2 tank pic is the green c74 next to my yellow s80...... the rest of the pics are the c74 tank.....

 

[Leadking]

"3AA" is a chrome molybdenum steel (ASTM 4130). Domestically sold steel tanks rated 3442 psi are not 3AA steel, they are carbon/chrome/ manganese/silicon steel (I believe) approved for sale under E9791 permit. Faber has sold some DOT3AA, 3180+ psi tanks in the USA but never a 3442 psi. In Australia, Faber is selling light weight, 3300 psi steel tanks with 7.0 diameter and various capacities. They could be high tensile steel or rebadged LP tanks made from 3AA. However, the test criteria are similar to E9791 (3/2 WP). I would like to know, myself, for purposes of continuing education.

3442psi steel clylinders are not made of the same alloy as LP cylinders. A special high strength steel is used. Read about it in the DOT special permit. A high stength steel was used to allow the use of LP tooling in manufacturing so that the same wall thickness is used.

I cannot stress enough that these are two different alloys

http://hazmat.dot.gov/sp_app/special_permits/docs/14000/SP14157.pdf

 

[Luis H]

Thanks for the PDF file.

It shows that the tensile maximum tensile stress allowed during hydro test is 90,500 psi for the Special Permit cylinders.

For 3AA the maximum allowed designed tensile stress during hydro testing is 70,000 psi.

It definitely has to be stronger steel. No surprises here.

 

[Nemrod]

Catalina does not make steel tanks I know of. This appears to be an aluminum tank with a 3,442 psi rating. Maybe they got tired of hearing how aluminum tanks are not heavy enough for "tech" diving whatever that is and now have manufactured a new series of "heavy" (as in negative) aluminum tanks with bouyancy characteristics similar to some steel tanks.

Beats me, serial number 0004 and not on their web page ? Australia? I might like to have a couple of them.

N

 

[Nemrod]

Here are the pics... the 2 tank pic is the green c74 next to my yellow s80...... the rest of the pics are the c74 tank.....

Just one thing, those fishnet things on the tanks, throw those away, all they do is cause the tanks to fall out of the cambands at the most diffucult moment. That usually yanks the regulator from your mouth and that usually causes a fair amount of consternation :no especially for all the guys who think doff and don is an ancient and no longer relevent scuba skill.

N

 

[DA Aquamaster]

Those plastic thingies, especially the large mesh ones like you have are great for snagging line as well. Take them off, stomp on them, throw them away.