How long do tanks last?

[docmojo]

i just read the thread listed luxfer AL80. I know you need the proper test but how long can you use these tanks bufore you might think about buying new replacement tanks. Also do steel tanks last longer or is the life of a tank about the same on all tanks.
Thanks for your help

 

[Soggy]

I've got a steel 72 from 1963 that seems to be going pretty strong. Aluminum doesn't last as long since they are more prone to sustained load cracking. A lot of it depends on how well you treat the tanks.

 

[mike_s]

Tanks last until they don't pass hydro or visual inspections anymore. Then they are "condemned".

The older (before 1989 I think) aluminum tanks made of a certain alloy are still good tanks, but they need to be better inspected to check for cracks etc. A small number of these had problems that caused them to rupture, etc. There is nothing wrong with these tanks as long as they are properly inspected, however, some dive shops choose not to fill them.

A steel tank doesn't really last any shorter or longer than aluminum in years.

 

[Spectre]

The only tanks that are technically limited in age are the high pressure [4500?] fiberglass tanks. They are more commonly used in SCBA [firefighters] and paintball guns [IIRC] and have a 10 year lifespan.

Personally I don't trust aluminums after 10 years, once they come up for their second hydro they are disposable in my eyes. but that's my personal feeling.

 

[akscubainst]

Actually it's 15 years for fiber wrapped and the new ones have 5 year hydro instead of just 3.

Aluminum tanks are designed for 100,000 fills or 10,000 hydro cycles. That doesn't mean every one would last that long but that is what they are engineered to do.

 

[rmannix]

My oldest steel tank is from 1967.
My oldest aluminums are a pair of 50's from 1976
I had an aluminum 80 from 1982 that developed a stress crack in the neck and failed visual in 1990. Didn't rupture, just leaked. Now it's a lamp.

 

[Spectre]

Actually it's 15 years for fiber wrapped and the new ones have 5 year hydro instead of just 3.

Ahh.. ok. Thanks for the correction.

 

[JustinW]

I have tanks in the rental fleet with an original hydro of 1955, still passed their hydro last year.

 

[XS Scuba]

The Limited Cylinders, manufactured by Luxfer are the only composite cylinders with a DOT exemption for scuba use. These cylinders require retesting by hydro every 3 years (not 5) and after 15 years these cylinders are to be removed from service. These have a working pressure of 4350 psi (not 4500). You can find more information at this link (part number ALW106) http://xsscuba.com/tank_alum_specs.html

Actually it's 15 years for fiber wrapped and the new ones have 5 year hydro instead of just 3.

Aluminum tanks are designed for 100,000 fills or 10,000 hydro cycles. That doesn't mean every one would last that long but that is what they are engineered to do.

 

[scubapro50]

I own 4 aluminum 80s made in 1984 ....... have no problems getting them filled by my local dive shop but took them to Florida and those guys wanted to rent me tanks because they said my old tanks were too dangerous to fill even thou they had just had a hydro last year and a current VIP inspection. Depends on the dive shop and how they feel about it ...............