well this bites...

[TheRedHead]

The tank problem would be a moot issue for me since my LDS won't even fill any pre-1988 Luxfer tanks, period. There very common on ebay for cheap prices because the sellers can't get them filled.

 

[JahJahwarrior]

Several tanks of this alloy have exploded. People have been hurt or killed and property destroyed. Those investigating the causes of the explosions have identified and named the failure mode and linked it to a specific alloy.

So far, the only credibility you have offered is that you said it. I would accept that, IF you could tell me that you actually know what you are doing. If you want to make your point strong, then you should give me a link to several specific failures. This is what my last post was trying to get across: I don't want you all to think you have formed an effective argument against me unless you can show me actual data. You have good points, you really do, and you all have gone a long way towards swaying me into not using this tank. However, you would not convince a judge. I happen to be on my high school debate team, and I'm working on a speech to perform in Original Oratory. I can write a great speech based on observations I've made in my own life, but it won't be credible. If I want a speech that has really strong points, then I need to pull in quotes from people, studies or statistics that prove my points. Until I do that, while I might be making good points, I'm not making valid ones. I've got tons of strong points from you all, tons and tons of them. I want some valid points. I want you all to show me something to prove your points can stand on their own.

 

[JahJahwarrior]

Tank Safety and Professional Inspection

By Jack Hornsby,
Professional Scuba Inspector and PADI Instructor
ASK Water Sports, Dublin, Ohio

"Most tank failures and injuries are due to factors normally found during the visual inspection process."



http://biobug.org/scuba/scubatank/

no author listed that I saw at first glance, but he seems to quote DOT.



"According the the US Department of Transport(DOT) In 1999, of the estimated 25 Million cylinders made of 6351 only 12 were reported to have ruptured."



"

On June 4, 1994, a second explosion reported to the DOT seriously injured Arnie Hubber, who was the fill station technician at the Scuba Sports Dive Store located in North Miami, Florida. He lost his right thumb and both his right arm and left leg were broken in addition to other injuries. The scuba tank in that explosion was manufactured in 1982, and had a current hydro (less than two years old) and a current VIP. It exploded while being filled to its rated pressure of 3000 psig. Arnie Hubber actually came to visit Chris in the hospital. In all of these previous explosions, a piece of the cylinder neck separated from the tank.
According to the DOT's safety alert in the Federal Register (Volume 59, No. 142, pages 38028-38030), the problem originates from the use of an inferior aluminum alloy to build these tanks. Alloy 6351-T6 has been used in the manufacture of seamless aluminum cylinders marked "DOT 3AL", and some composite cylinders. The DOT estimates that approximately seven million tanks have been manufactured using this alloy, with about two million being scuba tanks."



"

Points to Remember:

• The DOT issued a Safety Alert Bulletin back in 1994 regarding scuba tanks made out of alloy 6351-T6.
• The scuba tank that nearly killed Chris was made out of the 6351-T6 aluminum alloy.
• The DOT did not order a mandatory recall, nor did the manufacturers issue a voluntary recall.
• Annual inspections remove most of these tanks from service before they have a chance to explode. Some explode anyway."

Again, another person pointing out that most of these tanks are removed from service before they have a chance to explode.

I don't have any more time for this tonight, I have to pack up to go diving tomorrow morning.

 

[BHB ScubaTroll]

So far, the only credibility you have offered is that you said it. I would accept that, IF you could tell me that you actually know what you are doing. If you want to make your point strong, then you should give me a link to several specific failures. This is what my last post was trying to get across: I don't want you all to think you have formed an effective argument against me unless you can show me actual data. You have good points, you really do, and you all have gone a long way towards swaying me into not using this tank. However, you would not convince a judge. I happen to be on my high school debate team, and I'm working on a speech to perform in Original Oratory. I can write a great speech based on observations I've made in my own life, but it won't be credible. If I want a speech that has really strong points, then I need to pull in quotes from people, studies or statistics that prove my points. Until I do that, while I might be making good points, I'm not making valid ones. I've got tons of strong points from you all, tons and tons of them. I want some valid points. I want you all to show me something to prove your points can stand on their own.

Ah, the root of this troll...

Go do your own homework boy, and get off the bus to have someone here prove/disprove your theories.

Take your non-functional tank and put it on your wall of youthful mistakes. Or, do your homework and prove to us that the tank is safe. Until you do that, you are making good points, but not valid ones. The industry has determined that the tank you purchased is not safe. Prove to us that it is, or accept it.

You want valid points? Show us your valid points to prove the tank is safe. The industry has already determined that it is not. It is now up to you to provide proof that it is, or accept it.

We all want you to show us something to prove your points can stand on their own. We have the industry to show ours, now it is up to you to prove yours.

Remember, the industry has made a determination. It is up to you to prove otherwise, or the tank will parish as a valid SCUBA tank

If you are good at debate, this should be a piece of cake for you

 

[BHB ScubaTroll]

Tank Safety and Professional Inspection

By Jack Hornsby,
Professional Scuba Inspector and PADI Instructor
ASK Water Sports, Dublin, Ohio

"Most tank failures and injuries are due to factors normally found during the visual inspection process."
http://biobug.org/scuba/scubatank/
no author listed that I saw at first glance, but he seems to quote DOT.

"According the the US Department of Transport(DOT) In 1999, of the estimated 25 Million cylinders made of 6351 only 12 were reported to have ruptured."

On June 4, 1994, a second explosion reported to the DOT seriously injured Arnie Hubber, who was the fill station technician at the Scuba Sports Dive Store located in North Miami, Florida. He lost his right thumb and both his right arm and left leg were broken in addition to other injuries. The scuba tank in that explosion was manufactured in 1982, and had a current hydro (less than two years old) and a current VIP. It exploded while being filled to its rated pressure of 3000 psig. Arnie Hubber actually came to visit Chris in the hospital. In all of these previous explosions, a piece of the cylinder neck separated from the tank.
According to the DOT's safety alert in the Federal Register (Volume 59, No. 142, pages 38028-38030), the problem originates from the use of an inferior aluminum alloy to build these tanks. Alloy 6351-T6 has been used in the manufacture of seamless aluminum cylinders marked "DOT 3AL", and some composite cylinders. The DOT estimates that approximately seven million tanks have been manufactured using this alloy, with about two million being scuba tanks."

I don't have any more time for this tonight, I have to pack up to go diving tomorrow morning.

Excellent work!!!
You have shown everyone why these tanks are no longer valid.... great work!!

Now you understand why the tank you purchased will never be filled again!

 

[JahJahwarrior]

I disagree with you. Those points show there is a risk and that the risk of explosion is higher with this alloy. However, I found I believe two incidences of explosion, one which occurred while filling and anther which occured just before the tank was filled. Both tanks had been a year or two after a hydrostatic test when they exploded. I don't know how long I could use this tank for, maybe only a few dives. I'd retire it before a year.

I agree with you and cannot deny that the risk exists, however I believe I have shown it is lower than you all have stated. I also showed that several people, credible people, believe that the problems that cause failure in this alloy are usually found during a visual test, most notably cracks near the neck. That seems to me to say that if the tank passes a visual test and hydrostatic test with flying colours, it's good for atleast a few more cycles. A year or two down the road, maybe not, but a few fills?

I think you all have made your point and made it well, but I don't feel I am deserving of the animus displayed towards me in some of your posts. I feel I have done an equally good job of making my stand and having several others stand with me. I also feel I have not been very rude at all. I'm not here to start a fight, I'm here to gain respect. I'm not here to have you quote this line and say something mildly insulting, such as "you won't gain respect until you gain brains" or anything of that nature. I'm also not here to troll, spam or be an idiot. To label me as such is at best impolite and at worst, downright mean to a new scuba diver. It's all good, I won't sink to your level. I'll pm DennisW and try to gain from his knowledge, which seems to be vast and his comments show restraint and wisdom. Redhead also seems to know a good deal.

 

[Ed Palma]

The tank problem would be a moot issue for me since my LDS won't even fill any pre-1988 Luxfer tanks, period. There very common on ebay for cheap prices because the sellers can't get them filled.

Sorry Jah, I can see where youre coming from, but I have to agree with Red. The tank itself is kinda moot considering most shops won't fill it (nope, no hard statistics here...). Your tank may pass hydro and viz, but if you take it into the shop, you'll be faced with people who believe they are risking their lives. Even if you waved data and statistics in front of them, they have the final say (alternatives like a court-order would be too time-consuming and costly).

Remember, you might have the statistics and facts correct, but at the end of the day, what matters isn't who's right, but who's left.

 

[FredT]

The risks exist precisely because "visuals" vary across the board at the present time. As an ocean engineer, and PSI certified inspector, I'm quite aware that a thorough visual on an aluminum tank takes removal of all "stickers" and the boot if present and at least 15 minutes to do the inspection and note what is found clean then reinstall the valve with new O-ring. At that point it's ready to fill and install new EOE sticker. It takes time to do a good thread inspection, and to clean the thread surfaces before a valid inspection can be done. Internal pitting an external damage are relatively straight forward, internal cracks are a bit tougher to see visually. Properly calibrated NDT equipment takes a lot of the guess work out of the evaluation process, but the gear still must be operated and maintained by skilled trained personnel. That personnel is generally lacking in most dive shops. Most "operators" may actually know how to turn the machine on, but have little or no idea how the system works or what effects it's calibration. NDT equipment operation is not something that can be taught in a 2 hour seminar between parties at DEMA.

I have had tanks returned to me after vip and fill from the most apparently anal shop in the New Orleans area in considerably less than 10 minutes. Given that they tend to refuse to honor other entity's stickers it seems the vips could be a bit variable. I know for a fact some shops use the NDT system calibrated for 6351-T6 tanks on 6061-T6 tanks in direct violating of the manufacturer's instructions. This has proved to be a useless exercise that condemns sound tanks and costs the public serious $s. I've even seen the tools tried to be used on STEEL bottles! While an eddy current test can be performed on a steel tank, the equipment to do so is significantly more expensive than the visual plus hardware, by at least 2 decimal points. I designed, manufactured, and and used similar equipment on steel line pipe in the late '70s and early '80s. The company I worked for owned the patent on the process.


Once the tanks are hydroed and inspected for internal flaws with appropriate NDT gear by trained personnel whose ONLY job is to inspect cylinders with a strict pass/fail criteria the variability and reliability of that NDT inspection process will finally come under control.

 

[BHB ScubaTroll]

I disagree with you.

Oooh, the troll moto... too bad

Those points show there is a risk and that the risk of explosion is higher with this alloy. However, I found I believe two incidences of explosion, one which occurred while filling and anther which occured just before the tank was filled. Both tanks had been a year or two after a hydrostatic test when they exploded. I don't know how long I could use this tank for, maybe only a few dives. I'd retire it before a year.

Your points indicate the reason YOUR tanks will never be filled again.

I agree with you and cannot deny that the risk exists

read as: my point is given up, but I will not give it up because I don't want to...

, however I believe I have shown it is lower than you all have stated.

Huge and sad attempt to recover

I also showed that several people, credible people, believe that the problems that cause failure in this alloy are usually found during a visual test, most notably cracks near the neck.

NOT even important to the original question

That seems to me to say that if the tank passes a visual test and hydrostatic test with flying colours, it's good for atleast a few more cycles. A year or two down the road, maybe not, but a few fills?

I will stand by my $10.00 tank purchase, even though I have proven myself wrong.

I think you all have made your point and made it well

BUT

, but I don't feel I am deserving of the animus displayed towards me in some of your posts.blah, blah, blah (attempts to recover credibility)

We all want you to show us something to prove your points can stand on their own. We have the industry to show ours, now it is up to you to prove yours.

Remember, the industry has made a determination. It is up to you to prove otherwise, or the tank will parish as a valid SCUBA tank

 

[JahJahwarrior]

No, seriously Cooltech, 12/25000000 of them have ruptured, according to DOT as of 1999. I think my chances of winning the lottery might be around there too.

You are attacking me personally, an Ad Hominem fallacy and something I personally resent. Several people have taken this from an informative thread about the possible dangers of a 6351 alloy aluminum tank to a thread full of rude comments. That's annoying, at one point I was learning something in every post, now I'm being insulted in every post.