1989 Luxfer cylinder VIP refusals

[roakey]

Roak, I never argued that the crack wasn't there before, during, and after the inspection.

Phil, I was just answering mike_s' question of how did they know cracks existed for some time before other failures.

Now, the implication of what I am saying is that if there's oxidation, meaning it's an old crack and four inspections didn't detect it, you've got some pretty strong evidence that inspections can't always detect SLC. This may be the first solid piece of data that could cause an about-face in the industry's position. But I feel you need to get PSI involved to get this message out.

Roak.

 

[SparticleBrane]

Yet more reasons to dump at 6351 cylinders and only use 6061 (or steel).

 

[PhilEllis]

Phil, I was just answering mike_s' question of how did they know cracks existed for some time before other failures.

Now, the implication of what I am saying is that if there's oxidation, meaning it's an old crack and four inspections didn't detect it, you've got some pretty strong evidence that inspections can't always detect SLC. This may be the first solid piece of data that could cause an about-face in the industry's position. But I feel you need to get PSI involved to get this message out.

Roak.

I don't think that it is news to the dive industry and cylinder manufacturers that false negative results can come from eddy current inspection. It is also not news that spontaneous failures can result. I believe that the Chris Hawkins accident might well be an example of such.

I don't know the size of the remaining population of 6451-T6 cylinders used for scuba. I know that they estimated that there were two million of them sold to the market over the years. Luxfer bought back a large number of them with the rebate certificate deal. Many more have been removed from service by visual and eddy current inspection. Many more have been thrown out with the old dive gear in the attic. However, that population remaining is getting older and older. If Luxfer, PSI, the DOT. and the EPA are correct, time is a real enemy to the safety of these cylinders. There is some evidence that the testing routines have false negatives.

Why don't we simply remove these remaining cylinders from circulation. Of those currently in service, a couple of years of no fills, no inspections would weed them out. Why do we continue to have this debate when removing them through refusal would be so simple.

Remember, many people may well have a good intellectual understanding of these cylinders. However, there is nothing like the sound of a neck leak to demonstrate that the risk/reward associated with these cylinders is out of balance.

Anyway, just my view....against which all of those who want these to remain in service will argue.

Phil Ellis

 

[scubaskipper]

If this tank was in the questionable group. Aren't they suppose to be hydro stamped and a VE+ stamped also? The hydro place is suppose to do a VE inspection after the hydro. ( for this particular group of tanks) That should have shown any potential problems that wouldn't be able to be seen visually. If after all that' the tank still cracked, that had to be a pucker factor 10+.

I once worked at a shop that did monthly seminars. One month we did one on tank inspections. All the time, effort and expence that goes into it. We also had a binder full of the regulations involved with cylinder inspection. We had the owner of our hydro shop come in for questions after the presentation. We keep a good example of each type of problem to use in training of the tank guys. After the seminar, no one left feeling like they were getting ripped off with tank work. We would fill any tank that passed all inspections, no matter the age.

In Florida, the Keys tend to make blanket policies on tank issues. When I worked there, they didn't fill ANY steel tanks. It didn't matter the age, inspection status or condition! Basically, you can't tell a shop owner how to run HIS business. If he thinks the risk is too high, that's his choice. For those of you that think it's all about selling you a new tank, forget it. The margins are so low on alum tanks, the service is the better business model. You would have to sell an ungodly volume of tanks each month to make it worth keeping the doors open.

 

[Diveral]

I retired my 3 old 6351's after Phil showed me the tank that failed in his shop. Mine still hold air but were out of Hydro. I had discussed whether or not hydroing and continuing to use my old Al 80's (two of them dating to the 70's) with him while he was still inspecting and filling these tanks. I was still undecided when the tank failed and that made up my mind. i now use two HP 100's.

AL

 

[Wayward Son]

spooky stuff. I still have 2 of these, 100AL Luxfers. They're lovingly cared for at Sea Divers & I have no worries about them. But I don't want any more old ones & once I have enough steel tanks these 2 will likely be taken out of service altogether.

The aggravation factor of not being able to get fills away from home is reason enough now, but I can't really say I fault the shops. However small, there is some risk & if they don't want it, well, it's their business & their employees.

 

[WD8CDH]

I have no problem using my remaining 6351 tanks but I will not reccomend getting any more to anybody. The only reason that I still use my remaining 6351 tanks is they are in a size that was never made in 6061 alloy.

 

[mictrik]

I am on Long Island and seem to always get short fills especially with my 3500 PSI steel tanks. I have used these tanks since 1990 and I never got short fills back then (usually 3600 to 3800) but now it is the rule. Why? I want my tanks to be slightly overfilled as just about everyone did in the 70's and 80's.

I now do my own VIS, service my own regs and will likely all together stop going to dive shops once I find reasonable deal on a compressor.


Dive shops are notorious for making arbitrary stuff up when it comes to filling tanks. Witness the whole VIS thing, then the end of month/beginning of month thing with VIS's. And the re-vis/tumbling after coming back from hydro inspection.

I won't even get into the "short fill" thing. [/QUOTE]
am on Long Island and seem to always get short fills especially with my 3500 Psi steel tanks. I have used these tanks since 1990 and I never got short fills back then but now it is the rule. Why? I want my tanks to be slightly overfilled as just about everyone did in the 70's and 80's.

I now do my own VIS, service my own regs and will likely all together stop going to dive shops once I find reasonable deal on a compressor.


Dive shops are notorious for making arbitrary stuff up when it comes to filling tanks. Witness the whole VIS thing, then the end of month/beginning of month thing with VIS's. And the re-vis/tumbling after coming back from hydro inspection.

I won't even get into the "short fill" thing.

 

[deepstops]

I have no problem using my remaining 6351 tanks but I will not reccomend getting any more to anybody. The only reason that I still use my remaining 6351 tanks is they are in a size that was never made in 6061 alloy.

What size would that be??

 

[Web Monkey]

I am on Long Island and seem to always get short fills especially with my 3500 PSI steel tanks. I have used these tanks since 1990 and I never got short fills back then (usually 3600 to 3800) but now it is the rule. Why? I want my tanks to be slightly overfilled as just about everyone did in the 70's and 80's.

Energy is expensive. Banking more pressure than is necessary for their normal needs costs extra money. If 99%+ of the shops' business is 3000 PSI AL tanks and LP steel, they have no business incentive to bank 4000PSI just because a few people walk in with HP tanks now and then.

I now do my own VIS, service my own regs and will likely all together stop going to dive shops once I find reasonable deal on a compressor.

Dive shops are notorious for making arbitrary stuff up when it comes to filling tanks. Witness the whole VIS thing, then the end of month/beginning of month thing with VIS's. And the re-vis/tumbling after coming back from hydro inspection.

If you're doing your own VIP, I'm surprised anybody fills your tanks. You might not like it, but the inspections are as much for their protection as yours.

Terry