1983 aluminum scuba tank markings

[Pudsky]

Hey everyone, I have searched around and cannot find the info I am looking for. I recently got a scuba tank from a buddy. He gave it to me. If it is useable, I'll give him some money for it, if not he will get it back, so I am not out anything. Anyway, here are the markings on the tank, there is only one line.

DOT- 3AL 3000-J 13840 WK7A83

I do know that the tank was purchased in 1983, and used for three years. I believe the only hyrdo was the origional. It was VIP'd in 1983, 1984, 1986.

I cracked the valve and there is a little pressure still in it, so at the very least it is still sealed.

Thanks for your help.
Pudsky

 

[sardiverdan]

OK I'll bite...What kind of info are you looking for? You left that part out. Are you just trying to figure out what the numbers stand for???? Send it off for a vip and a hydro and see what they say. Just me but I would pass on an AL cylinder that is 27 years old.

 

[Pudsky]

Ok, so in more searching around the little interweb, I have dicerned that the tank is a Walter Kiddee from 1983. Apparently all Walter Kiddee tanks were made with the naughty aluminum alloy 6351-T6. So I don't believe this tank can be used. Oh well, it was kinda worth a try, and I learned a little more about tanks tonight.

 

[tregrrr]

'round here its worth about a buck a pound for scrap.... nice clean Al as far as the dealers are concerned.

 

[mpgunner]

I'd be surprised if a dive shop would touch it.

 

[mike_s]

.

DOT- 3AL 3000-J 13840 WK7A83

DOT= Department of Transportation
3AL = Aluminum alloy type.
3000= service pressure of 3000psi
13840 = serial number
WK
7^83 = hydro date of July 1983 (The A in 7A83 most likely looks like a 'Delta' )



All the 3AL Walter Kiddie tanks were 6351T alloy. So you won't be able to get it filled in lots of shops. So send it to the scrap yard. It's a paperweight.

Most shops don't want to touch any aluminum tank from before 1989 or 1990 'just to be safe'.


You might find this list usefull. (originally posted by LouisH)


Here is "The List" of scuba tanks that the DOT says are most likely made from the 6351-T6
aluminum alloy:

• All DOT-3AL tanks manufactured under one of the following exemptions or special
permits: 6498, 7042, 8107, 8364, 8422
• All composite cylinders manufactured under one of the following exemptions: 7235, 8023, 8115
• All DOT-3AL tanks manufactured under one of the following exemptions or special permits: 6498, 7042, 8107, 8364, 8422
• All composite cylinders manufactured under one of the following exemptions: 7235, 8023, 8115
• All Walter Kidde DOT-3AL scuba tanks.
• All Cliff Impact DOT-3AL scuba tanks made before July 1990.
• All Luxfer 80.8 cu. ft. scuba tanks (S80.8) made before May 1987.
• All Luxfer 72 and 100 cu. ft. scuba tanks (S72, S100) made before August 1987.
• All Luxfer 80 cu. ft. scuba tanks (S80) made before January 1988.
• All Luxfer 50 and 92 cu. ft. scuba tanks (S50, S92) made before April 1988.
• All Luxfer 30 and 63 cu. ft scuba tanks (S30, S63) made before May 1988.
• All Luxfer 40 cu. ft. scuba tanks (S40) made before June 1988.
• All other scuba tanks made in the US before February 1990 (except Catalina).
• All scuba tanks not made in the US.
Unless proven otherwise, all scuba tanks in the above list should be assumed as being
made using the 6351-T6 alloy.

 

[Troutmaster]

You can make a really cool mailbox or lamp out of it. The valve may also be salvagable, but the tank should not be used as a tank.

 

[Scared Silly]

This FAQ might be of help:

http://www.scubaboard.com/forums/ta...66-my-cylinder-made-bad-alloy-aka-al6351.html

 

[DennisW]

Actually if the cylinder passes hydro and a VIP+ (by the way the only reason for the eddy current test is for the sustained load cracks that may be found on the 6351 alloy cylinders), there is no reason to not use the tank. However, many shops will not fill them anyway and that is their prerogative.

I have a perfectly good Walter Kidde tank that I have retired for this reason (although I know of two shops that will still fill it). I plan to make a lamp out of it one day.

 

[mike_s]

Actually if the cylinder passes hydro and a VIP+ (by the way the only reason for the eddy current test is for the sustained load cracks that may be found on the 6351 alloy cylinders), there is no reason to not use the tank. However, many shops will not fill them anyway and that is their prerogative.

a couple years ago I would have agreed with you 100%.

However, I saw a 6351T alloy tank that just passed a hydro by a certified hydro facility and an Eddy test that developed a hairline crack in the neck the first time it was filled after hydro. (the crack was in the tank neck and not the threads so the Eddy test would have not seen it).

Prob from the stress of the hydro. The crack was so small that you couldn't see it unless someone pointed it out, put a bright light on it and perhaps used a magnifying glass.

maybe this was a one time case, but if other 6351 tanks develop this issue it's not good.

so now I see why LDS's don't fill them. At least why my LDS doesn't.