New guy with a good question

[1Scubanewbie]

So many questions...so little time! Hello to all. Great forum! I probably should have came here first; however, I ran across 3 US Divers Aluminum Tanks at a garage sale and purchased them all for $50. All of the tanks are out of hydro and may have been stored open. Is this okay? How do I determine if they're usable? I figure the worst case scenario is I'm out $50. ;-0

 

[Great Puddles]

Depending how old the tank is, you may just need it visually inspected for internal corrosion and hydro tested.

I remember from my SCBA training that some older aluminum air cylinders made before 1990 may be defective. There is a DOT bulletin floating out there about this. I'll see if I can find anything.

 

[HarleyDiver]

Welcome to the board.

Your first stop is at your local dive shop.
Have a qualified tech inspect them, and if there are no visible signs of corosion, then have them Hydro'd.

What is the date of the last Hydro?

If they suspect the tanks are faulty, they won't even try to hydro them.
In that case you will have a great lamp base (or 3).

Good luck.

 

[Great Puddles]

Here is some information about aluminum tank ruptures:
http://www.psicylinders.com/library/cracking.htm

And the DOT notice it references is here:
http://hazmat.dot.gov/rules/not99_11.htm

Find of off topic, but in checking these websites out, I came across this:

http://www.napsd.com/cscuba.htm

In this article, it recommends that tanks be stored upright with 50 PSI in them. This is contrary to what I've been taught about storing tanks. I was always told that the tanks should be stored full b/c in case of fire, a little bit of heat will increase the pressure and break the blow-out valve, and the tank will safely deflate. Whereas a tank that is near empty will require so much heat that by the time the pressure reaches dangerous levels, the blow-out valve is already melted.

 

[Paco]

If they're good, you've found quite the deal. Let us know how they work out. And welcome to the board.

 

[1Scubanewbie]

Thanks for the replies. I especially like the comment about lamp bases....funny. A big thanks for the links, I'll visit these and take a look. A tank rupture sounds like a painful event....or painless depending upon whether you live or not! The tanks were last hydro'd in 1983.

 

[1Scubanewbie]

Man, I went through those articles and it seems to me the best thing to do is to discard the tanks. Since they were manufactured before 1983 by Luxfer they are of the inferior grade of aluminum. I'm not sure after reading the last article that an inspection would ease my concern. I'm not sure you would even know if your tank inspector really knows his/her stuff. Not knowing the history behind these tanks makes me a little more than nervous.

 

[herman]

1Scubanewbie once bubbled...
Man, I went through those articles and it seems to me the best thing to do is to discard the tanks. Since they were manufactured before 1983 by Luxfer they are of the inferior grade of aluminum. I'm not sure after reading the last article that an inspection would ease my concern. I'm not sure you would even know if your tank inspector really knows his/her stuff. Not knowing the history behind these tanks makes me a little more than nervous.

There is a lot of mis-information/half truths running around about these tanks. Yes there IS a minor problem with them forming stress cracks BUT if you look, in the 10s of thousnds of them around the world, only a very few of them have exploded. And in all the cases I am aware of, all the tanks that did explode were out of vis and most likely hydro as well. The failure mode of these tanks take YEARS to develope and there is ample time to discover the cracks before anything goes wrong.
Do a search on this board on the subject, there were some very good responces to this question over the years.

If you still want to get rid of them, I will give you the $50 back and pay shipping.

 

[ddown]

Luxfer will give tou 50.00 credit toward a new tank for of those tanks.

Tom

Just sent some off myself

 

[GlockDiver]

If cylinders that have sit a long time get corrosion in them, can they be treated and put back into service?