Tank that has been engraved

[Rhone Man]

My thought is that if you have an engraved tank, the sensible thing to do is exactly that: go and have it tested. If it passes, it passes. If it doesn't, well better you find that out in the safety of a hydrostatic test tank than your LDS finding it out in their compressor room.

Every tank I know that has failed hydro has failed at the top or the bottom, so my gut instinct would be that you have room to play with on the walls. But my opinion counts less than 5/3rds working pressure worth of water.

But as someone posted above, it may just be one of those: "rules are rules" things.

 

[redacted]

My thought is that if you have an engraved tank, the sensible thing to do is exactly that: go and have it tested. If it passes, it passes. If it doesn't, well better you find that out in the safety of a hydrostatic test tank than your LDS finding it out in their compressor room.

Every tank I know that has failed hydro has failed at the top or the bottom, so my gut instinct would be that you have room to play with on the walls. But my opinion counts less than 5/3rds working pressure worth of water.

But as someone posted above, it may just be one of those: "rules are rules" things.

Unfortunately, passing a hydro is not just a matter of passing the pressure test. Tanks may well pass the pressure test but other "defects" (dents, pitting, etc.) may cause the failure without regard for the pressure test result.

 

[CAVDVR93538]

Sounds to me like he's getting something for nothing. The hydro doesn't have anything to do with the scratch. When a tank comes in for hydro and filling out the precursory paper work the tank valve is removed and the stickers are peel off as a 1.courtesy to ther hydro company 2. they have to come off anyway to "vis" the tank AFTER it comes back from hydro. Then pass: continue the rest of the "vis" or fail: the tank failed hydro and the "vis" isn't necessary.
If the tank went through hydro, then you owe for that service.
If the inspector wants to condemn the tank based on external irregularities, before it has went to hydro, then the inspector hasn't really done anything other than refuse the tank.
What's the charge for? refusing to "vis" the tank. Bull Sh..
It is still your property and he isn't suppose to do anything until you have been notified, in writing. And then either pay for hydro or get a second opinion.
I would find out who holds his tank inspector credentials. PSI, IANTD, TDI.... and ask that company for an opinion. They are not suppose to destroy the tank until ALL of the findings, evidence, 2nd opinions, etc. are conclusive and YOU sign off stating that they have permission to destroy the tank, especially if the problem is suspect.
There is a process to condemn a tank:
OBTAIN Signed Customer Authority (required)
Get 2nd opinion
Notify customer
Stamp "CONDEMNED" or
XX out markings (except hydro and serial #)
Destroy Valve Threads
For what it's worth

 

[RickPeck]

Aluminum scrap is going for over $1 a pound. The hydro tester is probably getting money for the "condemned" tanks. If he refused to do the hydro and visually inspected the tank, you (I think) would still owe some money for the labor. I would pay the $25 and sell the tank for scrap if you don't want to re-hydro.

Best Regards,

Rick

 

[Scared Silly]

Sorry, no pics. The guy condemed the tanks. He wanted $25 for my friend to get the tanks back and he told him to....well take a guess.

Where was the cylinder taken exactly? A dive shop or directly to the re-qualifier (hydro shop)?

If the engraving was that obvious that the cylinder was immediately condemned many shops (whether a dive shop or hydro shop) will simply condemn the cylinder and return it with out charge. My local hydro shop did way more with a old steel that failed the actual hydro and did not charge me.

Second as said, it is your property. It should be returned. However, they do have a right to be payed for their services no matter how minimal. If they said the test cost $25 and waived it in lieu of keeping the cylinder and selling for scrap that would be fine. But they had better say that up front.

 

[CAVDVR93538]

I agree, most shops donot have hydro abilities at the store, they send the tanks out. a 2nd opinion is definitely in order. The "hydro stamp" or any other things of that nature are suppose to be between the neck and tank shoulder. If tanks failed vis for minor scratches even if the scratch was artistic, most all tanks would fail loading them in your truck.
Again, for what it's worth.

 

[adelman]

The more I think about this...

I would take an ultrasonic depth gauge to the tank and measure the sidewalk thickness. Measuring the depth of the damage is more difficult, but at least estimate an upper bound. A good stereo microscope can help here, if you have access to one Then I'd talk with the tank manufacture to see if that is allowable damage.

I talked with Catalina recently regarding an isolated severe pit in an Al6. Their position was that there is a minimum undamaged wall thickness specified by DOT as related to the tensile strength of the material. Since there is some manufacturing variability, you need to make an actual measurement of the wall thickness, and get the allowable minimum from the manufacture. I suspect if the depth of the engraving doesn't intrude into the required wall, their position would be that it doesn't matter.

PSI trains that an isolated pit can be 0.060 deep, but Catalina says a tank could pass their manufacturing QA right down to the minimums, so in theory there could be tanks out there for which NO damage is allowable. Although I'm a PSI-trained inspector, I'm going to say that I'd go with what the manufacture says.

No matter if the hydro facility already condemned it. If they were wrong, they owe you a tank. Measure the sidewalk thickness carefully before you engrave the new one

 

[05sportsman]

I think it will be hard to get a hydro shop to put their stamp saying it is good on a tank that is rated for 3000 psi with a stamping, engraving in the sidewall. Think about it, stamping in the sidewall is not allowed even though you aren't physically removing any metal compared to an engraving that has removed metal from the sidewall. I will look in my reg book tomorrow and get the exact paragraph.

 

[adelman]

I think it will be hard to get a hydro shop to put their stamp saying it is good on a tank that is rated for 3000 psi with a stamping, engraving in the sidewall. Think about it, stamping in the sidewall is not allowed even though you aren't physically removing any metal compared to an engraving that has removed metal from the sidewall. I will look in my reg book tomorrow and get the exact paragraph.

Stamping affects the metallurgy deeper down than the stamp itself; it work-hardens the material which is displaced. Engraving would not. Is the DOT prohibition a "thou shalt not stamp on the sidewall" or "thou shalt condemn tanks stamped on the sidewall". It would seem to me that engraving should be evaluated like any other nick or scrape; but then again, I'm using common sense and that might not apply to the DOT. What does the DOT have to say about them?

 

[adelman]

I think it will be hard to get a hydro shop to put their stamp saying it is good on a tank that is rated for 3000 psi with a stamping, engraving in the sidewall. Think about it, stamping in the sidewall is not allowed even though you aren't physically removing any metal compared to an engraving that has removed metal from the sidewall. I will look in my reg book tomorrow and get the exact paragraph.

I think the problem is 49 CFR 178.35(f)(6) "Other markings are authorized provided they are made in low stress areas other than the side wall and are not of a size and depth that will create harmful stress concentrations. Such marks may not conflict with any DOT required markings."

So basically, if the engraving were accidental damage, it might be allowable, but if you construe it as "Other markings", and it is on the side wall, then it is unauthorized and the tank is condemned.