Question regarding aluminum tanks manfg in 1981

[fweber]

Problem is 6351-T6 Alloy.
Any cylinder manufactured before 1990 marked 'DOT-3AL'
[/IMG]

You're painting a slightly inaccurate picture. Not ALL cylinders manufactured before 1990 are made from 6351. Catalina cylinders have always been made from 6061 and shouldn't be subject to these issues.

The big problem is: Shops making knee jerk, gut based decisions in the face of suitable procedures and practices. There is absoutely no reason that an annual visual with some form of eddy currecnt avaluation shouldn't catch a developing neck crack long before it becomes a threat.

To the OP. Check with your local lds. If they're willing to fill them after a vis and hydro, and they should be, then you're good to go.

 

[Nemrod]

See the thread just below this one---the tanks pre 89 that are made of the 6351 alloy will not be filled in many places, right or wrong, those tanks are worthless but for scrap. N

 

[Going The Distance]

Ok: Just Got This Tank Hydro. I kept it in the shed for about two years after exp and kept on thinking will it make it or scrap it.. It passed.. I know its a 3000psi/80. Man date 89. My question is even if it passed Hydro Is it safe.. #s are as follow CTC/DOT-3AL3000P422555Luxfer A89-s80.

Thats fine if the shop passed it, but if its a potential hazzard I dont want the guy filling it to get hurt. Granted It would of been nice to know before they sent it out... Thanks for any info reguarding this.

Going The Distance.

 

[Scared Silly]

GTD - your cylinder was mfg in 89 which is after Luxfer stopped using 6351-T6 so you should be fine. As mentioned, you may be subject to the whims of the dive shop used to fill it.

I.e many have said no AL cylinders made before 1990 some are going as far as no cylinders more than XX years old.

 

[Doubles]

Well there are certain tanks my shop will not fill for the simple reason that their DOT exemption is expired.

And that is a justifiable reason not to fill the those tanks.

But there isn't any reason not to fill a tank that has passed a proper hydro/vip test and and where the DOT exemption is still valid or as been renewed

I wonder how many folks performing VIP tests are actually qualified to do so?

Cheers

Steve

 

[igotag!]

You're painting a slightly inaccurate picture. Not ALL cylinders manufactured before 1990 are made from 6351. Catalina cylinders have always been made from 6061 and shouldn't be subject to these issues.

That is why I said POTENTIALLY affected...

If you are unsure if your tank is affected or your unsure if your tanks exemtion letter is still active go Hazmat Safety List of Special Permits for a list of all exemtion letters. If a tank has an expired exemption letter a shop can not fill it.

 

[Xefe]

us d
ctc/dot/e6498
p366063

p304856



These are the numbers and markings on the tank. (via phone)

 

[captain]

I don't know the accuracy of this but here it is.

Sources - A Brief Scuba Cylinder History

 

[Scared Silly]

us d
ctc/dot/e6498
p366063

p304856



These are the numbers and markings on the tank. (via phone)

USD - US Divers

e6498 This is the exemption number which AL cylinders were first mfg under.

p366063/p304856 serial number.

 

[DA Aquamaster]

There were 3 or 4 exemptions for AL tanks that were all combined into the single 3AL standard. Tanks with those exemptions were/are supposed to be restamped "3AL" at their next hydro test.