Older unused tanks ok?

[Arcadie]

I began diving in 2000 and bout 4!tabks within the next 3 years. These tanks range from 2k1 to 2k3. I have used them until about 2k6-2k7. Since then I they have just sat in the garage with around 300 psi each as I used operator tanks after that. Now that my wife got certified I wanna use these again but only if it's safe. They are al80's from luxfer.

Obviously they will need a VI's and hydro. But is there some anomalies or odd issues fillin tanks that have been sitting with only a couple hundred psi for 10 years to 3k psi? Something maybe a hydro or VI's won't detect?

 

[TrimixToo]

Unless they got salt water in them, they will be just fine. Have someone shine a light inside first, and if they're dry, go get them hydroed, cleaned (if necessary), and VIPed.

 

[Colliam7]

But is there some anomalies or odd issues fillin tanks that have been sitting with only a couple hundred psi for 10 years to 3k psi? Something maybe a hydro or VI's won't detect?

Nothing that I know of, or have ever heard of. In fact, the argument could probably be made that they are close to 'good as new' since they have not been subjected to repeated pressurization / depressurization.

 

[Luis H]

The hydro test measures the material condition. It indirectly measures the elasticity of the material (material ductility) by precisely measuring its volume expansion and most important how much (if any) residual permanent expansion/ deformation is left, after it was pressurized to the designed test pressure. This is a indicator of the material condition.

The material condition can be degraded by events like the tank being in a fire or exposed to high heat (like with some of the high temp painting processes). The heat will degrade the aluminum heat treatment process that was done at the factory. The hydro test will pick this type of defect that otherwise is not detectable by other means like the visual inspection.

The visual inspection is intended to pick up any surface imperfections, including; pits, crevices, dents, corrosion, and any other surface imperfections.

Between a properly performed surface visual inspection (both inside and out) and the hydro test, you have covered the potential structural defects that can compromise this type of cylinder.

Note: I mention this type of cylinder because my statements only apply to the newer aluminum cylinders made out of 6061-T6 aluminum alloy (or any steel cylinder). Yours falls in this category.

 

[Curtis C]

I just had one of my aluminum tanks hydro'd and VIP'd. It had been sitting in the basement with 400 PSI in it for 17 years. No problems with it passing.