life span of aluminum tanks

[Jambi]

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.

From the sounds of is this practice seems common. I was under the impression that the visual inspection was DOT mandated. Correct me if I am wrong but, should that not include the requirment of being properly trained and certified through a DOT approved program? If the above is correct then does that make all the VIS and VIS+ inspections done by anyone other than a certified inspector invalid? Perhaps it is just me be it seems that something as important as a VIS should have a quality control aspect to it's inspectors.


Jambi

 

[LUBOLD8431]

NO, the annual visual is an industry supported program. There is a requirement of a visual before and after a Hydro test, and yes, that is required by DOT, but only every five years for most cylinders...

So, if your LDS lets a moron "shop monkey" do your visual, its completely legal... (emphasis on the fact that they might not even KNOW what to look for...)

 

[Jambi]

Thanks! LUBOLD8431,
You learn something new every day. For some reason I am still not reassured to have a :mfight: do my VIS. Oh well.

Jambi

 

[Moogyboy]

This may be an old question but here goes: do tanks have a useful service life before I should start thinking about retiring them? I have an aluminum 80 which used to do training/rental duty at my LDS, so it's seen heavy use. The oldest hydro stamp is from 1989. That's, ah, a long time ago. And also those horror stories I hear about tanks made before that date blowing up...anyway, I wonder.

cheers,

Billy S.

 

[Moogyboy]

Wow, I guess this WAS an old thread. Thanks for relocating my post into it.

Billy S.

 

[The Chairman]

There is no DOT visual required at any time... only hydrostatic testing every five years. if the tank passes the DOT mandated Hydro, and the industry mandated yearly Visuals then it is indeed sea worthy. I would not hesitate to dive them.

 

[roakey]

Wow, I guess this WAS an old thread. Thanks for relocating my post into it.

I always send mail to the base author when I combine threads, but you have your board mail turned off, so I'm glad you found it!

Roak

 

[pasley]

This may be an old question but here goes: do tanks have a useful service life before I should start thinking about retiring them? I have an aluminum 80 which used to do training/rental duty at my LDS, so it's seen heavy use.

Ahmmmm, there is a reason the dive shop is retiring a tank and then going to the expense of buying a new replacement. As you said, rental tanks see heavy use. You may use if for many years before it fails hydro, and then again, it may fail the very next hydro. Consider the cost of new tanks and the years of use you will get out of them. Bottom line is there is a limite to the life of a pressure vessle. What that is depends upon many factors including overfills (hard on tank) and heat amoung others. If there is a Sports Chalet (AKA Evil Empire) near you, Catalina AL80 with new valve and a fill are $109.00 all year long.

 

[FreeFloat]

I own a Walter Kidde tank, made of 6351-T6 alloy. I have it visually inspected and Eddy Current tested more often than mandated. So far, not only has it passed with flying colors but the last inspector commented he had never seen a tank in better shape.

That hasn't stopped me from keeping an eye out on a good deal for a replacement tank though because eventually I'll find very few shops willing to fill it regardless of how recent its last tests were........ paranoia can run deep and far. If I do replace it most likely it will be with another steel tank like my other tank is.

 

[Moogyboy]

Ahmmmm, there is a reason the dive shop is retiring a tank and then going to the expense of buying a new replacement. As you said, rental tanks see heavy use. You may use if for many years before it fails hydro, and then again, it may fail the very next hydro. Consider the cost of new tanks and the years of use you will get out of them. Bottom line is there is a limite to the life of a pressure vessle. What that is depends upon many factors including overfills (hard on tank) and heat amoung others. If there is a Sports Chalet (AKA Evil Empire) near you, Catalina AL80 with new valve and a fill are $109.00 all year long.

UPDATE: I finally deciphered the markings on my tank and discovered that it's a Catalina aluminum 90 first hydroed in January 1989. As I understand it Catalina was using 6061 alloy even then, so presumably my tank isn't subject to the problems that the 6351 tanks are. Sigh of relief.

cheers

Billy S.