Help deciphering tank stamp

[gopbroek]

With the recent threads on the ability to have an AL80 tank Hydro’d plus the fatal accident in Cozumel yesterday, I was wondering if someone could decipher the tank markings on a couple tanks I purchased several years back in a lot of Craigslist equipment. In 2011 I took both down to a local shop for inspection and Hydro and they accepted one but rejected the other as ‘too old’. As I understand it the limitation is not only on age but primarily on the alloy it was constructed with. Aluminum alloy 6061-T6 being bad, alloy 6351 being OK.
If anyone could decipher these markings I would appreciate it.
Accepted tank:
TC-3ALH 207
DOT-3AL 3000 P280113 LUXFER 11A96 S80
Rejected tank:
DOT 3AL 3000-J 05947 WK 3A83
On the rejected tank I am assuming the manufacture date was 83 which definitely puts it in the suspect age group but I am unsure of the manufacture.

 

[tbone1004]

you have the alloys backwards, 6061=good/new, 6351=bad/pre88

TC-Transportation Canada
3ALH canada's aluminum standard
207-service pressure

DOT-US DOT
3AL-US Al standard
3000-working pressure
P280113-Serial number
Luxfer-mfg
11a96-birthday of November 1996
s80-tank model number



Rejected-
DOT-US DOT
3al-US Aluminum gauge standard
J-05947-serial number
WK-Walter Kidde
3a83-Birthday March 183

Walter Kidde tank was made of the same 6351 dangerous alloy as the old Luxfers. While they can pass hydro/vip, very few shops will bother with them and quite a few will refuse to fill them even if they're in current hydro/vip.

hope this helps.

 

[gopbroek]

you have the alloys backwards, 6061=good/new, 6351=bad/pre88

TC-Transportation Canada
3ALH canada's aluminum standard
207-service pressure

DOT-US DOT
3AL-US Al standard
3000-working pressure
P280113-Serial number
Luxfer-mfg
11a96-birthday of November 1996
s80-tank model number



Rejected-
DOT-US DOT
3al-US Aluminum gauge standard
J-05947-serial number
WK-Walter Kidde
3a83-Birthday March 183

Walter Kidde tank was made of the same 6351 dangerous alloy as the old Luxfers. While they can pass hydro/vip, very few shops will bother with them and quite a few will refuse to fill them even if they're in current hydro/vip.

hope this helps.

Well that answers that, and thank you

 

[tbone1004]

no worries mate. They're all basically the same for aluminum or steel. Steel becomes 3aa and doesn't have the capacity markings on the cylinder but the rest of them are the same. Sometimes the manufacturer will be in a weird logo stamp the rest are standardized

should also be noted that Walter Kidde never changed alloys in their aluminum tanks, so unlike Luxfer where the Pre-88 rule applies to the safe alloys, all Walter Kidde aluminum tanks have the 6351 alloy.

 

[Scared Silly]

but rejected the other as ‘too old’. As I understand it the limitation is not only on age but primarily on the alloy it was constructed with.

Age has absolutely nothing to do with the issue. In this case it is strictly the material, AL6351. Everything else that tbone said is spot on.

 

[Blue Quaker]

Technical note....3ALH doesn't exist in Canadaian specs.. I think the OP meant 3ALM. "M" stands for metric pressure = 207 BAR

 

[tbone1004]

Technical note....3ALH doesn't exist in Canadaian specs.. I think the OP meant 3ALM. "M" stands for metric pressure = 207 BAR

I thought that was strange since I've only ever seen 3alm too, but figured it could have been an old standard.....

Too old though does have some merit as a lot of shops won't fill a 15yr+ aluminum tank, or will at minimum require Eddy testing on it for neck cracks. I replace mine at the end of their 3rd hydro anyway. For $150 for a new al80 without a valve, it's not worth the hassle

 

[Trance]

I have a friend who lent me a couple of his tanks which are Professional AquaLung/US Divers from 78/79. Last hydro in 84. Local shop took them, passed hydro, and refills them. Wonder if I should cease using them or not. Local shop even replaced a valve for me...

 

[scubadiver888]

I have a friend who lent me a couple of his tanks which are Professional AquaLung/US Divers from 78/79. Last hydro in 84. Local shop took them, passed hydro, and refills them. Wonder if I should cease using them or not. Local shop even replaced a valve for me...

If they are steel, no worries. If they aluminum they are probably 6351 alloy and subject to Sustained Load Cracking (SLC). If it is 6351 alloy you can do an Eddy Current Test on them. If they pass the eddy current test then they should be good. Some shops will still not fill them.

 

[Trance]

Thanks for the info. They are AL80s, a bit off on dates but here they are if this helps in decisions of safety.