life span of aluminum tanks

[SDAnderson]

Actually, ALL aluminum tanks will eventually fail because of sustained load cracking if filled enough times.
Happily the minimum number of fill cycles designed into the tanks is a minimum of 10,000, a number that's probably going to take a heck of a long time to rack up.
You're looking at almost 100 years if used on average of twice a week.

Heh. I'll be dust long before that - close enough to "indefinitely" in my book.

granthammer: This is what happens when you try to save a few dollars by buying from the street - what you save in dollars you will need to make up for in knowledge. It might end up being faster/cheaper/safer to buy a new one from a local dive shop. There's a term for that often applies to the old beater tanks found stuffed in the corner of someones garage - wind chimes. Be careful and don't forget to get up to speed on the valve, too.

Good luck!

Steven

 

[pasley]

I don't think the alloy is all that big of a deal if you get the tanks eddy current tested every year with the viz. But I'm not a tank geek.

Out of the thousands of tanks out there, the number of tanks that have exploded is quite small, I agree. But, if you happen to have the tank in your car, house, garage or be near it when it goes, well, you whole day could be ruined. Some tanks have let go in a very violent manner with little or no notice in as little as six months after passing a VIS and with a current Hydro.

So do what you want, but as for me, I don't want to be any where near them. I can buy new AL 80 with valves at my LDS for $109.00. Saving a buck is not worth losing your hand, leg or life over.

DOT is still working of the issue and I have no idea what the Canada authorities are doing. Right now, DOT is happy with continued testing and VIS Plus testing. But as have been stated, some dive shops are refusing to fill the older AL tanks, particularly the suspect alloy ones. I don't blame them, it is there safety they are looking at.

 

[BrianM]

The thing I am constantly amazed by is the high prices paid for used aluminum tanks!!!! I saw an AL80 on ebay last week got $152 before shipping!!

They opened a new Sports Chalet near my house with a SCUBA department....they are selling brand new catalina's for $109 bux and you pick the color (I like cool anodized blue)!

Why in the heck would someone want to by an old tank, and wonder if it will pass the next inspection, when you can buy a new one so cheap with a warranty, new valve, new hydro, visual and a free fill ?

 

[Axeman]

Although they are still legal in Canada we do not fill these tanks at my store.

While it may be an acceptable risk to you it is not to me. These tanks typicly fail on filling

I will be they guy near the tank while you are browsing in the show room. Therefore I will be the guy who dies or becomes an amputee if it fails.

Also the risk is higher for me because I fill and handle tanks all day whil eyou just have the one alumibomb in your trunk.

so in the end I would pass on any tank made with this alloy

I have in my shop some pictures of shops and people after an explosion and when I show these to a customer they ask me to dispose of their tank and they buy a new one. At a great price too, cause I want them and me to be safe rather than making a buck.

Here is an excet from Luxfers web site. I would recomend avoiding any tanks that fall into years made with this alloy regardless of manufacturer.

10. How can I tell if my Luxfer cylinder is made from 6351 alloy?

The easiest way is to check the original hydrostatic test date stamped on the cylinder crown.


Luxfer manufactured 6351-alloy cylinders during the following periods:


United States: 1972 through mid-1988


England: 1958 through 1995


Australia: 1975 through 1990


Luxfer

 

[roakey]

Axeman, are you a trained and current visual inspector? If so, though what orginization?

Roak

 

[Axeman]

Axeman, are you a trained and current visual inspector? If so, though what orginization?

Roak

Like most up here in Canada I was trained by the store owner. They have been in business for over 30 years and I had to inspect all tanks with them for 6 months before I could do them on my own. And I still pass on anything suspicious to them for dbl checking.

We do Vis and Vis+ here as well as hydros. I am the only Hydro operator here and trained to TC specs.

 

[roakey]

Like most up here in Canada I was trained by the store owner.

Ok, Is the store owner a trained and current visual inspector? If so, though what orginization?

Roak

 

[LUBOLD8431]

Actually, ALL aluminum tanks will eventually fail because of sustained load cracking if filled enough times.

I thought one of the big selling points of the 6061 alloy was that it was NOT susceptible to SLC. I actually had quite a conversation with one of the guys at Luxfer about this, and he told me that SLC was IMPOSSIBLE with the 6061 alloy (Luxfer cylinders) because of the molecular makeup, or some such scientific talk.

 

[Axeman]

I am really not sure... why do you ask.... I believe I saw a cert in his office but that is at another store.... so I can't say.

 

[LUBOLD8431]

Most dive shops train their employees to do visuals, and they get no certificate, no diploma, or anything. This training is hurried, partial, and money driven. Come on, a visual is $8-10!!! The dive shop owners want their money. I once asked the LDS that I used to work for if I could go to a PSI class (it was held on a saturday, and I normally worked sat) and he said "NO!!! Thats a waste of time." The funny thing is, this same LDS will NOT fill any cylinder that has a PSI visual sticker on it. The cylinder has to have a sticker from a dive shop on it. He didnt honor the PSI visual. I thought that was funnny... AFAIK, this LDS owner never had any formal training for visuals. He did have a certificate for hydro retester, however.