Hydro data- steel 72 pressures and REE

[duckbill]

Follow-up post....

Your hydro tester doesn’t seem to know what he is doing.

Added:
Don’t be surprised if that tank fails hydro in the near future. By pressurizing it above the test pressure he is getting more permanent expansion than it is designed for (going into the low end of the yield strength) and therefore he has worked hardened the tank some. It may not have any consequence, but it may.

Well, Luis, I just had these cylinders hydrotested since they were due for it.

One of them, while it didn't fail, had an elastic expansion that was right at 58.4. This is a Norris cylinder, not PST, but I would imagine the plus rating is now gone (this was its 9th hydrotest), most likely thanks to the over-pressurization done by the previous hydrotester we were talking about. This one is relegated to 2250psi only now. TestP 3760psi; Total 62.0, PE 3.6; EE 58.4, Pass at 5.8%

The other cylinder passed fine (PST- 6th hydrotest): TestP 3760psi; Total 55.9, PE 0.4; EE 55.5, Pass at 0.7%

A couple questions...
What happens if, at the next test, the EE is lower? Is it possible for a cylinder to lose the "+" numbers at one hydro, then get them again in a subsequent hydro? What would you do under those circumstances?
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P.S. Before posting this, I just now called the hydro facility that did this last test to confirm if the rounding-out procedure was performed as requested. It turns out that it was NOT done, so the numbers could be off. I guess next time I will have to send the PST D-100 document with the cylinders, or better yet, take them in myself and talk with the hydro-tester. Apparently he is not aware of this procedure for galvanized cylinders.

 

[spectrum]

P.S. Before posting this, I just now called the hydro facility that did this last test to confirm if the rounding-out procedure was performed as requested. It turns out that it was NOT done, so the numbers could be off. I guess next time I will have to send the PST D-100 document with the cylinders, or better yet, take them in myself and talk with the hydro-tester. Apparently he is not aware of this procedure for galvanized cylinders.

This would seem to go full circle to your prior quote of Luis H, "Your hydro tester doesn’t seem to know what he is doing".

As for a future test you can always try for + in the future. Sometimes it's simply not sought but if it passes in the future it passes. Given the numbers equipment and methods involved measurement system error surely results in some discrepant results.

Pete

 

[duckbill]

This would seem to go full circle to your prior quote of Luis H, "Your hydro tester doesn’t seem to know what he is doing".

Not full circle, as this is a different hydrotester. I'll never be going back to the tester that overpressurized my cylinders as per the op.

I'm finding NO hydro tester seems to know 100% what he is doing. If it isn't one thing, it's another. Not knowing about the rounding-out procedure when one is a fire extinguisher hydrotester is much more forgivable in my book that being an exclusively SCUBA hydrotester who routinely and excessively overpressurizes cylinders.

I never ask for a plus any more. I just look at the EE so I know for myself if I can fill them the plus 10%. Those get a simple Sharpie "+" next to the hydro stamp.

 

[scubafanatic]

Not full circle, as this is a different hydrotester. I'll never be going back to the tester that overpressurized my cylinders as per the op.

I'm finding NO hydro tester seems to know 100% what he is doing. If it isn't one thing, it's another. Not knowing about the rounding-out procedure when one is a fire extinguisher hydrotester is much more forgivable in my book that being an exclusively SCUBA hydrotester who routinely and excessively overpressurizes cylinders.

I never ask for a plus any more. I just look at the EE so I know for myself if I can fill them the plus 10%. Those get a simple Sharpie "+" next to the hydro stamp.

Almost wonder if your hydro tester has an 'agenda', namely that if he REALLY over hydros the crap out of tanks, only the toughest (safest) tanks will survive, and he's doing some sort of public service ? or maybe getting kickbacks from local dive shops who benefit from selling replacement tanks ?

 

[akdeepdiver]

Did the original hydrotester brought up at the beginning of this post get reported to the DOT? Is he still doing hydrotests?

 

[duckbill]

Only he could have known if he had an agenda.

Did the original hydrotester brought up at the beginning of this post get reported to the DOT? Is he still doing hydrotests?

That was five years ago, but I had reported that his license was not valid at the time. The DOT didn't seem too concerned over the phone, but I did notice his license was renewed shortly thereafter.

As best as I can tell, he is still licensed, but the DOT page is not up-to-date, the latest update being sometime last year. Big surprise, huh? Since you brought it up, I checked online for his business and I think that he has also recently moved. He may even be retired for all I know.

Through this latest experience with this other hydrotester I've learned that fire extinguisher retesters don't normally deal with galvanized cylinders, and are therefore mostly unaware of the rounding procedure recommended (read "required") for them. My next cylinders are due to be tested in two years, at which time I will personally deliver them and try my hand at educating. That doesn't usually work out too well with professionals who "have been doing this for twenty-some years, so I know what I'm doing. Blah, blah, blah...", but I'll try to remain optimistic. Maybe I'll just have to resort to offering to pay a few bucks more if they would swear on their mother's grave that they'll just do it!

 

[imjustdave]

I think you just need to be upfront with the tester. Hey do you have experience in scuba tanks? Do you have experience in galvanized tanks? Do you know they have a special test? By the end of this conversation you will know if the person is up to the task.