Steel tank failure.....at hydro facility....no BOOM!

[phreaticus]

I traded a set of 104's for a set of steel lp (2400) 80's (plus cash), around six years ago, for use as rebreather and sidemount bottles. Both tanks were in hydro, good for three and two more more years, at the time. I had one hydro'd when it ran out...passed with no problem. Used them (and filled them myself, despite the one being out of hydro....both tanks clean visually every year) maybe a dozen times over the past four years. Decided to get the one hydro'd a couple weeks ago, ...took it to the local hydro facility...and they said they could not test it because the serial #'s were not legible.....I looked , only three #'s are discernable, it looks like they "over galvanized" the area over the serial #'s. The hydro facility even tried wire brushing away the excess "coating', to no avail.
Does anyone know if there is any recourse to get this cylinder replaced...I believe it is a Pressed Steel manufured tank? Or is the original warranty only to the original owner?
Just a shot....never seen this occur before, in over 40 years of dealing with SCUBA cylinders.

Thanks

[Greenwood_60]

They may be Worthington tanks. There was a period of time where they were having trouble with their tanks, and I believe it was due to too thick of galvanizing as well. They even had to update their hydro procedure, as many tanks were failing. Check the original hydro mark. Post a pic, and I'm sure someone can match it to a known tank. I'd call the manufacturer, once you know who it is.

[Jay]

Steve,

Did you take it to Dave at Advanced Hydro in Homossassa? If not then give him a call at 352-422-1234. He may have current info on the PST's or be able to tell you what it was.

[Jon Nellis]

Zinc is very reactive to hydrochloric acid (muriatic acid, commonly used for swimming pools and available at most hardware stores). You could brush a little acid over the area to dissolve the zinc out of the letters and then neutralize with a baking soda and water rinse. You might get a little corrosion on the steel, but it will only be minor as steel does not react/dissolve as fast as zinc and will not hurt the tank. The reaction will produce a bit of hydrogen gas, so no smoking.

Give it a shot of cold galvanizing spray and spray your new hydro stamp at the same time.


Cheers,
Jon

[huxley]

Get an x ray of the tank. This should show the number, even if you grind it out.

[phreaticus]

Thanks to all....good suggestions....
It may, after all , be not worth the effort, just wondered if others had seen this problem....

[DA Aquamaster]

The irony here is that it passed it's initial qualification by an independent testing company. It has not "grown" more galvanizing since then.
I suspect the RIN may be a little too picky - if it has 3 discernible numbers, that's the serial number and will be sufficient to ID the tank with no real need to over think it.

I'd try another tester whose a little more willing to look at the practical reality and intent of the serial number in this situation.

[huxley]

not sure if serial is a requirement at hydro facility you might want to call another one. They had to scratch my fabers down since it was almost impossible to read the stamps. They scratched the old hydro mark down to metal to see when they were stamped original. Not that I would bring tanks to hydro facility that don't need to!

[dnscarboro]

Will need number however call me we can help you with it....or pm wwwcylindervalveinc.com I'm in Marianne later this month and Lake City Set 27th. Be glad to help you with it. We are based in Metro Atlanta if you have anyone coming up this way-I know several cave divers that travel to cave country almost every week. It is not an uncommon issue.

[dnscarboro]

PS the other people did not XXX out the serial number or anything like that??? They should not have but just wanted to ask.