Hmmm.... Phil Ellis' experience in this area casts a long shadow over the whole process... Being a "what happens in the real world" kind of a guy, I'm leaning towards retiring 6351 tanks as they run out of current hydro.
Rick
Hydro question
- Thread starter BigDustyman
- Start date
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Rick
Scared Silly
Contributor
Good information here. A couple small additions.
The term VIP is really a scuba industry term. A visual inspection is performed. But more over the term "hydro" test really refers to the whole requalification process which includes a visual inspection and a hydro static test. And as many now know for 6351 cylinders an eddy current test.
I am confused by this as it has only been since 2007 that the eddy current has been required to be part of the requal process. Eddy current testing has been around 8+ years now and I have never read anything from Luxfer or any of the other related material saying the above.
Luxfer: Press Releases
Everything I have read from Luxfer said they required the test every 2.5 years.
Luxfer: Press Releases
But the dive industry did roll it into the annual visual inspection.
The last two points are really moot now that the eddy current test is required at the time of requal. However, I am sure many dive shops will be telling people that it is required every year.
The term VIP is really a scuba industry term. A visual inspection is performed. But more over the term "hydro" test really refers to the whole requalification process which includes a visual inspection and a hydro static test. And as many now know for 6351 cylinders an eddy current test.
I am confused by this as it has only been since 2007 that the eddy current has been required to be part of the requal process. Eddy current testing has been around 8+ years now and I have never read anything from Luxfer or any of the other related material saying the above.
Luxfer: Press Releases
Everything I have read from Luxfer said they required the test every 2.5 years.
Luxfer: Press Releases
But the dive industry did roll it into the annual visual inspection.
The last two points are really moot now that the eddy current test is required at the time of requal. However, I am sure many dive shops will be telling people that it is required every year.
Last edited:
I eddy after the hydro, the DOT log indicates the visual is preformed after the the cylinder has been stretched and logically that is when the damage should be noticed.
It makes no sense to look for cracks before. Of course I have always thought it was funny that I stretch the tank, check it for cracks, pitting, gouges and fatigue. If everything is ok I take a steel punch and a big hammer and smack the heck out of it to put new gouges into it.
To answer the original posters question, we don't care about the last test date of any tank, aluminum or steel. Well, that is not completely true there were a few special permits that did not receive exemption status and expired. They can not be requalified. Carbon fiber wrapped tanks are the pain right now.
If you have the money I'll test it. If it passes, it passes. If it don't you have a hunk of scrape to do what ever you like.
I see no problem with a dive shop requiring eddy current testing with VIPs on AL cylinders, so long as they represent it as their own requirement.
"The government requires eddy current testing on some older aluminum cylinders with hydro, Luxfer recommends it every 30 months; we require it on all aluminum cylinders with every VIP."
"Why?"
"'Cause we're paranoid... "
Rick
I took my AL80 tank (not Luxfer - others used 6351 alloy too) in for a fill a couple weeks ago. Somehow it got mixed up and taken to the LDS's Hydro facility for a Hydro. It wasn't in need of a Hydro yet, but a few month away. It came back condemned. They never even put it under pressure. I was told the new rules REQUIRE the Hydro facility to the eddy current exam BEFORE Hydro testing. The new report is computer generated, and just summarizes that problem....something anyone could do with a word processor program. They stamped out the DOT 3AA .... numbers with XXXXXX. They said that there was a crack in the neck that spanned 2 threads.
I didn't get a graph printout like the old tests, which I was trained to read, not via the scuba industry, but the space industry.
My shop says the Hydro facility does the Eddy current before hydro, and if it passes, then hydro, and stamped the date and V+. Then my shop does another eddy current and their visual and put a VIP+ sticker on it. My tank didn't make it that far
So, now I'm in the market for another tank or two. I was planning on using my AL80s as twins also using that configuration when traveling, since all I'd have to do is mount 2 AL80s and put regs on each and go. It also simplifies things when you are renting tanks, or taking them in for fills. Or, so went my thinking. Now, since I have purchase another tank or two (my other AL80 is this ones sister....same dates) I'm debating on getting some E7-80s or something in steel (not huge) instead.
I didn't get a graph printout like the old tests, which I was trained to read, not via the scuba industry, but the space industry.
My shop says the Hydro facility does the Eddy current before hydro, and if it passes, then hydro, and stamped the date and V+. Then my shop does another eddy current and their visual and put a VIP+ sticker on it. My tank didn't make it that far
So, now I'm in the market for another tank or two. I was planning on using my AL80s as twins also using that configuration when traveling, since all I'd have to do is mount 2 AL80s and put regs on each and go. It also simplifies things when you are renting tanks, or taking them in for fills. Or, so went my thinking. Now, since I have purchase another tank or two (my other AL80 is this ones sister....same dates) I'm debating on getting some E7-80s or something in steel (not huge) instead.
Scared Silly
Contributor
In my reading of the CFRs the order of the tests are not specified.
So a search on HP80s and doubling them up. Head heavy is the key word.
That is just what I was told. Although, I guess it makes sense to run the test that is most likely to fail first, if you don't have to run any other test once any test fails. And, I suppose it is easier (less setup time) to run the eddy current test.
I just saw some of those posts. Currently I'm wearing 4-8 pounds on my upper cam band to help push my head down. I have little flotation in my skinny legs. So, I'm wondering just how much "head heavy" are they? I'm checking around, but very few of the local LDS's have anything but AL in their rental line. In fact, there are only two LDS's that I am aware of that will even talk/teach tech diving.
I may just go back to AL80s, (not the 6351 alloy though!).
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