Buying used tanks

[Crimediver]

I have 40 + tanks of all kinds and I have a compressor so I am not worried about getting my tanks filled, including the 6351 alloy. I don't blame a shop for not filling the 6351 alloy tanks. it is their choice. Not filling any tank that is not 6351 alloy that has a current viz and hydro is a BS marketing ploy to attempt you to buy new tanks. I would call them on it and take my business elsewhere. And tell my dive buddies to do the same.

[mm2002]

Originally Posted by Crimediver

I have 40 + tanks of all kinds and I have a compressor so I am not worried about getting my tanks filled, including the 6351 alloy. I don't blame a shop for not filling the 6351 alloy tanks. it is their choice. Not filling any tank that is not 6351 alloy that has a current viz and hydro is a BS marketing ploy to attempt you to buy new tanks. I would call them on it and take my business elsewhere. And tell my dive buddies to do the same.

I can understand your thinking (kinda), but what I don't get is why people continue to gamble on an alloy that has proven to be a potential disaster. A brand new AL 80 is less than $150, c'mon. Current vis and hydro? A vis done 10 months ago is still considered current, but what happened to the tank in that 10 months? Hydro is even worse....5 years! What can happen within those 5 years? I have a favorite saying from my mechanic days.....NOTHING IS EVER BROKE TILL IT'S BROKE........Then it may be too late to worry about it.

[navyhmc]

True MM. I can see both sides of the issue. As Joe has said once on the 6351 subject, while there are literally millions of 6351 tanks out there and only a handful have failed (though more are failing eddy currents) so the risk is actually small on a tank to tank comparision, the number of fill stations worldwide is less than 20,000 so the risk of a catastrophic failure rises on a per location level. Different ways to look at the same issue.

As for the SLC's and catastrophic failures, I haven't heard of any in the past few years. I would hazard a guess that this is due to 1. Tanks are not being filled and are being scrapped. 2. A limited number of fills stations are filling them and 3. (probably the biggest influence) the annually required eddy current testing.

[mm2002]

Originally Posted by navyhmc

As for the SLC's and catastrophic failures, I haven't heard of any in the past few years. I would hazard a guess that this is due to 1. Tanks are not being filled and are being scrapped. 2. A limited number of fills stations are filling them and 3. (probably the biggest influence) the annually required eddy current testing.

I'd have to agree. To sum it up, the reason we're seeing less failures is because there's a lot less of them in service. As a safety margin, I think they should all be scrapped, but some folks seem to want to hang onto them for whatever reason. I don't get it. I have some sitting here with the valves off, just waiting to be part of some project. I have several ideas, but nothing is carved in stone. If we could come up with more creative ways to recycle them, maybe more would be decommissioned.

Table lamps???.....oh that's so cliche....

[ScaredSilly]

Originally Posted by navyhmc

As for the SLC's and catastrophic failures, I haven't heard of any in the past few years. I would hazard a guess that this is due to 1. Tanks are not being filled and are being scrapped. 2. A limited number of fills stations are filling them and 3. (probably the biggest influence) the annually required eddy current testing.

Note - there is no annual "required Eddy Current test - just whatever malarky the dive industry tried to put forth. Starting Jan 2008 the eddy current test is required only at the time of requal (aka Hydro). If an eddy current test was done then the requal test date should be followed by a "VE" stamp.

[navyhmc]

That's interesting, do you have a link?

Not doubting you at all Scared Silly, but I just can't see me going to the LDS to get a Vis and tellig them that the eddy current is no longer an annual requirement and citing "Scared Silly ffrom the Scuba Toys forum" as my reference. They might look at me like I'm just a little more nuts than normal.

[ScaredSilly]

Hazardous Materials: Aluminum Cylinders Manufactured of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, and Oxygen Services--Revised Requalification and Use Criteria | Federal Register Environmental Documents | USEPA

What the dive industry did before this requirement was do an annual eddy current test as part of the annual industry standard of a VIP. However, Luxfer recommended the eddy current test every 2.5 years. DOT basically took out of their hands and said it will be done at the time of hydro. Of course many shops did not get the memo (for that matter some hydro shops).

However, none of this matters as the dive shops can (and do) make up whatever rules they want. I do not mind the scuba industry coming up with their own standards but there is not a lot of consistency at times.

[navyhmc]

You're of course right on all accounts ScaredS. Thanks for the link!

[enigmata]

I recently bought a used steel 72 original hydro in 1972, most recent in '08 still going strong...