reading tank stampings

[gypsyjim]

I am looking for a link to information on reading tank stampings. I used to have it, in my paperwork, and know I have seen links here in SB, but damned if I can find anything useful with SB "search".

I am going to look at some tanks over the weekend that the seller has no info on at all, as they are in an auction of tools and household stuff, and I wanted to do some homework before I drive out there.

 

[coglesby]

There are several websites that give the info....but try this one:
ScubaGoneWild::Scuba Class::Scuba Tank Markings

 

[gypsyjim]

Thanks, I did several searches, both on the net and here in SB. It is amazing how much information is available out there. It is equally amazing how mush useless stuff you sometimes have to wade threw before you find exactly what you are seeking!!!

 

[coglesby]

Yes, indeed!

 

[herman]

Hi Jim,
A little more for you, 3AA is chrome molly steel (a steel tank) and 3AL will be aluminum. If you see an E or SP in place of 3AA or AL it's a special exemption and most likely one of the older grades of AL, best pass on it. There is nothing wrong with old steels however some have tapered threads and some dive shops will not deal with them so the best bet is stick with ones that use the 3/4 diameter threads and have an oring at the top of the tank. Unless you are wanting vintage, if you see threads or teflon tape, pass on them.

 

[JohnB47]

Hi Jim,
A little more for you, 3AA is chrome molly steel (a steel tank) and 3AL will be aluminum. If you see an E or SP in place of 3AA or AL it's a special exemption and most likely one of the older grades of AL, best pass on it. There is nothing wrong with old steels however some have tapered threads and some dive shops will not deal with them so the best bet is stick with ones that use the 3/4 diameter threads and have an oring at the top of the tank. Unless you are wanting vintage, if you see threads or teflon tape, pass on them.

The PST 3500 psi tanks have 7/8" threads. Those are ok also, as long as they pass the hydro and visual inspection, but they do take special valves, and those valves have DIN fittings.

 

[knotical]

And for European cylinders:

Tank Markings identified, what do they are all mean?

 

[gypsyjim]

Thanks knotical, I have a copy of that too now, but I am hoping it is tanks from US or Canada that I find.

 

[Guy Alcala]

Hi Jim,
A little more for you, 3AA is chrome molly steel (a steel tank) and 3AL will be aluminum. If you see an E or SP in place of 3AA or AL it's a special exemption and most likely one of the older grades of AL, best pass on it. There is nothing wrong with old steels however some have tapered threads and some dive shops will not deal with them so the best bet is stick with ones that use the 3/4 diameter threads and have an oring at the top of the tank. Unless you are wanting vintage, if you see threads or teflon tape, pass on them.

It's just if not more likely to be a high pressure steel tank than an older Al tank. The HP tanks will have E or SP followed by a 4 or 5 digit number. If you google the letter/number combo, it will normally bring up info on the company that made the tank. E9791 is PST, E or SP 14157 is Worthington, and ISTR that Asahi (Genesis) and Norris both had 'E' followed by five digit numbers starting with 12 or 13, but don't remember what they are offhand. I don't know the number for Faber. Edit: Asahi is E or SP12079.

Guy

 

[gypsyjim]

I just spoke with the autioneer, again, and asked for some info on what he has there. He knows nothing at all about the stuff, except the one larger tank was last inspected in '91! Other 2 tanks are a bit smaller, and still on the old BCD's, so can't he see the stampings.

The one tank he could read:
line #1: X (or so it sounded like)K ICC 3AA2250
line #2: (he is hard to understand, but it sounded like A18164

Sounds to me like 20+yr old steel tank, last tested 19 yrs ago. Obviously this gear is going to be pretty darned old, and has been sitting a while, but I guess I just have to drive out to the auction and see what it looks like. Probably just wasting the gas, but it's always worth looking, just to learn.