Good Deal on a Tank

[FishFood]

Seems to be a lot of fear mongering about the old aluminum tanks around here. Just to balance out the forum I figured Id share my latest purchase. It's an Aqualung/US Divers Aluminum tank from 1979 (complete with a J valve ). Popped up on craigslist and I grabbed it. Came with a current hydro even. My LDS just did a visual and eddie; Said it looked good! Total cost - $34.

[cbrich]

I see a lot of misinformed people about the 6351 aluminum tanks. I was looking on Luxfer website about the failures of the 6351, and they listed 6 failures in the United States, 4 of which resulted in injury. 3 of the injuries where in Florida where, I have come believe, they were propably over pressured to 4,000 psi.

I have 6351 tanks and non of them are experiencing SLC.

You came across a hell of deal.

[ScubaToys Larry]

Originally Posted by cbrich

I have come believe, they were propably over pressured to 4,000 psi.

Actually the one at force E blew up when bleeding pressure, and it was around 2300 psi. Resulted in very bad injuries to the shop employee.

There are very few places around us that will fill them, but if you have a place that will, and are comfortable with them, that is about a 100 savings over a new tank.

[in_cavediver]

The problem is tanks are relatively cheap, dive shops don't make money on air and its a pretty poor risk/reward situation for the fill operator.

Why should I, who is most likely losing money or just breaking even, risk myself filling a tank with a known issue that can/has caused catastrophic failure before. The chance is small but the reward is small too - especially when a much safer alternitive exists.

There is a reason luxfer did the buy-back. There is a reason the DOT modified the hydro test procedures for these tanks. There is a significant potential for a problem and that problem can have catastrophic consequences.

Can they be used safely - sure. My VFD has them. Do I like them - nope and we are doing are best to get rid of them. I do a lot of the fills for our SCBA's for some reason (I am one of maybe two or three who are actually trained in HP gas handling/filling). I don't like them. If I had the choice (and resources), we get rid of all of the 6531 tanks we have. (goto carbon fiber of course but thats another discussion)

[longtailbda]

The problem were having in this area is that the hydro companies will no longer hydro older tanks. According to the 2 in our area their insurance companies will deny coverage if there is an accident with these older tanks.

The shop itself has about 20 tanks that are going to have to replace due to this.

[cummings66]

As to cave fills on AL cylinders, that to my knowledge does not happen on purpose. I've seen a couple accidentally filled to 3500 psi but never on purpose. The general belief is that only steel is safe to cave fill.

I don't think it's fear mongering either to point out that there were failures and that there was a concern about them that warranted additional testing.

I am surprised a DOT hydro facility would refuse to hydro them, mine will do that and he's not concerned about it. In fact every one I know of will hydro them.

[in_cavediver]

Originally Posted by cummings66

As to cave fills on AL cylinders, that to my knowledge does not happen on purpose. I've seen a couple accidentally filled to 3500 psi but never on purpose. The general belief is that only steel is safe to cave fill.

I don't think it's fear mongering either to point out that there were failures and that there was a concern about them that warranted additional testing.

I am surprised a DOT hydro facility would refuse to hydro them, mine will do that and he's not concerned about it. In fact every one I know of will hydro them.

I too am extremely suprised to hear the hydro facilities aren't willing to do it. I could believe not being able to to do them due to the lack of eddy current machine but realistically, there is minimal risk. The pressurization is done with water which is non-compressible so even a catastrophic ruture is pretty much a non-event.

[cummings66]

My local hydro facility told me he was required to buy the eddy current test machine, he had no choice. So, for what it's worth I think it's somebody passing the buck. I wonder if it's more likely to be the dive shop saying the hydro facility won't do X when it's really the dive shop.

Hopefully he'll post back and reinforce it was the hydro facility and not the dive shop that made the claim. Of course, insurance does drive a lot of things, or the lack of it drives things.