Decommissioning my AL tanks

[Brendon]

cut in half lengthwise, add a hinge and a grate... BBQ!

Let's think about that for a second... Uhm no, these are aluminum not steel. For many reasons that is a bad idea... Not to mention you wouldn't have much grill space.

 

[Scared Silly]

I have read the Federal Register over a year ago, where the DOT was saying that these tanks had a useful life of about 35 years.

FYI, DOT did not make that statement. What DOT did was propose a 40 year life span requirement in regards to DOT's solicitation for comments on AL6351 cylinders.

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

However, there was no evidence that supported making such a rule for cylinders made from AL6351. As such, Al cylinder when properly inspected can be used indefinitely.

 

[simonbeans]

Finally the voice of reason. Thank you Scared Silly. I heard once that a kid fell down his front steps. I propose that we need more regulation for steps and make it a law that all people under the age of 103 wear protective gear when using steps. If you want to feel better, then hang the suckers in your garage and let your survivors worry about them in the future.

 

[John C. Ratliff]

Originally Posted by John C. Ratliff View Post
I have read the Federal Register over a year ago, where the DOT was saying that these tanks had a useful life of about 35 years.

FYI, DOT did not make that statement. What DOT did was propose a 40 year life span requirement in regards to DOT's solicitation for comments on AL6351 cylinders.

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

However, there was no evidence that supported making such a rule for cylinders made from AL6351. As such, Al cylinder when properly inspected can be used indefinitely.

Scared Silly,

I understand what you are saying. And I understood it when I first read the regs (although I did not remember exactly the time that they had suggested for a life span for these cylinders). Here is what the Federal Register actually says concerning the 40 year life span:

B. 40-Year Service Life

Currently, cylinders manufactured of aluminum alloy 6351-T6 may be
used indefinitely so long as they conform to the requalification test
and inspection criteria established in the HMR. The SNPRM proposed a
40-year service life from the date of manufacture for DOT 3AL cylinders
manufactured of aluminum alloy 6351-T6 and used in SCUBA, SCBA, oxygen,
and carbon dioxide services. Several commenters [CGA; Air Liquide;
Barlen] to the SNPRM oppose the 40-year service life proposed for DOT
3AL cylinders manufactured of aluminum alloy 6351-T6. These commenters
suggest there is no evidence these cylinders are more likely to be
susceptible to SLC as they age and state the proposed amendment lacks
the appropriate test data, analysis, or statistical data to support the
implication that older cylinders are more likely to develop SLC. These
commenters further suggest requalification is the most appropriate
method to identify and condemn DOT specification cylinders regardless
of their age.

After consideration of these comments, we agree our proposed 40-
year service life for cylinders manufactured of aluminum alloy 6451-T6
and used in SCUBA, SCBA, carbon dioxide, and oxygen services is not
warranted at this time. We also agree with the commenters' [CGA; Air
Liquide; Barlen] statements that the requalification process is an
effective method of condemning deteriorated or damaged DOT
specification cylinders. Further, there is evidence these cylinders are
being voluntarily removed from service as defects are identified
through inspections and testing. Therefore, we are not adopting the 40-
year service life in this final rule. We will continue to monitor
cylinders manufactured of aluminum alloy 6351-T6 for evidence of SLC. If
the situation warrants, we may revisit this issue in a future rulemaking.

Realize that I do not know the history of these cylinders before I bought them. They do have a special coating, which was not put on by the manufacturer and may have involved a heating process. They have seen a lot of use, and have remained pressurized for long periods of time. I do realize that the eddie testing/visual inspection most likely will find any problem, but there comes a time when there are diminishing returns for keeping them in commission. I am keeping this in mind as I put my UDS-1 back into commission, and it has these type of tanks too.

But if I have a choice between my UDS-1 and these twin 50s, the UDS-1 wins. And that is part of my choice here. Also, I have two new sets of steel twins, a 52.8 cubic foot set of USD tanks and my newly commissioned twin 42 PJ Jump Tanks. If I had a choice between my twin AL 50s and either of these, I would pick the steel tanks, and I do have that choice.

At work I just decommissioned four SCBA 4500 psi AL cylinders, as they had reached their 15 year limit. I have four more to decommission within the next year. While Simonbeans feels that these twin 50s could last forever, I am not so sure. Aluminum is a softer metal, and a 35 to 40 year life span is quite enough I think.

Dale, I like your suggestion of keeping them for display purposes. I am probably going to do that.

SeaRat

 

[John C. Ratliff]

Finally the voice of reason. Thank you Scared Silly. I heard once that a kid fell down his front steps. I propose that we need more regulation for steps and make it a law that all people under the age of 103 wear protective gear when using steps. If you want to feel better, then hang the suckers in your garage and let your survivors worry about them in the future.

Simonbeans,

I respect what you are saying, but that is not how I view this discussion. I have been a safety professional and industrial hygienist for over 30 years now, and can tell you that some of the most effective safety programs are not built on regulations, but on being prudent about matters.

Concerning the kid falling down the stairs, there are child gates for that, and it does not take a regulation to go to the store and buy them (I had them when my kids were young).

I'll probably put together a display of a double hose regulator with those tanks (see above), as visually they could be very appealing. But I will try to bring my USD-1 system, with its three AL tanks, back to life (bad fill hose which I need to repair/replace right now).

SeaRat