Steel Tank Condemned: Cracks in Threads?

[Barnaby'sDad]

I recently purchased a pair of used HP steel tanks. The last vis for both tanks was in 2019, so it hasn’t been long since they were inspected previously. Both tanks were filled, but I went ahead and dropped them off to get inspected just to be on the safe side.

One will be getting condemned due to cracks in the threads. Just curious...what are the odds that the cracks occurred in the past year and were not simply overlooked by the previous inspector?

I’m guessing that there’s no way to really make an educated guess on that, but again...just curious.

I realize that there’s nothing that I can do here and I’ll get to look at the tank prior to the shop officially condemning it. More frustrated at the fact that I spent $150 for a 30+ lb paperweight than anything else. That and wanting to make sure that I learn something from this and don’t run into this again (though it seems to be a coin toss with used tanks, from what I’ve read here).

Next time I buy used, I guess I can throw out there to offer to pay for the vis first to make sure that they’re good. Either that or I can buy two and get one next time, too.

 

[lexvil]

It’s how things work, until there were cracks the weren’t cracks, maybe they were there and missed on the last viz or maybe they weren’t, there is no way to know.

 

[tbone1004]

@Barnaby'sDad was it condemned at VIP or condemned at hydro?

Dive shops are not legally allowed to condemn a tank without the customers permission. I.e. if they stamp anything out or drill it or whatever to permanently condemn a tank without your direct permission it is against federal law. Only DOT inspectors are allowed to condemn pressure vessels without the owners permission.

It is HIGHLY unlikely that there was actually a crack in the threads...

 

[michael-fisch]

If they are steel tanks, I would not let the shop do anything to the tanks! Cracks in the threads are a problem on old Luxfer Alum tanks made befor 1989, but I've never heard of cracked threads on a steel tank. While I don't want to proclaim that your dive shop doesn't know what they are doing, without further proof, a strong possibility exists!
Take the tanks to a facility that does hydros and have them hydro'd. If they pass that, then avoid your dive shop like the plague and spread the story so that many others will also avoid that shop.

Michael

 

[Barnaby'sDad]

@Barnaby'sDad was it condemned at VIP or condemned at hydro?

Dive shops are not legally allowed to condemn a tank without the customers permission. I.e. if they stamp anything out or drill it or whatever to permanently condemn a tank without your direct permission it is against federal law. Only DOT inspectors are allowed to condemn pressure vessels without the owners permission.

It is HIGHLY unlikely that there was actually a crack in the threads...

It was condemned at VIP. They made it clear that they want me to look at the tank (they said that proactively) and would not stamp it as condemned until I have a chance to look at it.

The shop in question is meticulous, in my experience. I’ve spent a good amount of money with them and they have no reason to hose me over a used tank. By being thorough, they’re actually losing money, as they won’t be charging me to O2 clean and fill that tank as a result of the cracks.

I thought this seemed odd, but like I said...I don’t think the issue is with this shop. I would be far less surprised to hear that the last inspection wasn’t as thorough as it should have been.

 

[rhwestfall]

Seeing it is a steel tank, I'd certainly like to see the crack(s)....

It is proper they show you before condemning the tank, unlike a hydro-tester who can without your permission.

 

[shurite7]

Hm, from what I learned in courses and experience, steel tanks are not known for cracks in the threads. The 6351 alloy of AL tanks are known for cracking due to sustained loading (SLC). This doesn’t mean I didn’t check for cracks on steel tanks.

A visual inspector cannot condemn your tank without your written authorization, which the inspector/shop should have had you sign when you dropped the tanks off. Also, it is highly recommended to get a second opinion before damnation. I, nor my hydro tester, condemned a tank without both of us looking at it. For unusual cases we brought in a third person and/or contacted the manufacturer.

As for good customer service, the shop should have asked you to come into the store so that you could see the crack before it was condemed.

 

[Barnaby'sDad]

If they are steel tanks, I would not let the shop do anything to the tanks! Cracks in the threads are a problem on old Luxfer Alum tanks made befor 1989, but I've never heard of cracked threads on a steel tank. While I don't want to proclaim that your dive shop doesn't know what they are doing, without further proof, a strong possibility exists!
Take the tanks to a facility that does hydros and have them hydro'd. If they pass that, then avoid your dive shop like the plague and spread the story so that many others will also avoid that shop.

Michael

The vast majority of shops in my area don’t do hydro inspections. They ship them out and have them done offsite.

If I show up and there’s visible cracks, it’s getting binned or I’ll hack it up for something. If it’s not cracked, I’ll figure something else out.

Hm, from what I learned in courses and experience, steel tanks are not known for cracks in the threads. The 6351 alloy of AL tanks are known for cracking due to sustained loading (SLC). This doesn’t mean I didn’t check for cracks on steel tanks.

A visual inspector cannot condemn your tank without your written authorization, which the inspector/shop should have had you sign when you dropped the tanks off. Also, it is highly recommended to get a second opinion before damnation. I, nor my hydro tester, condemned a tank without both of us looking at it. For unusual cases we brought in a third person and/or contacted the manufacturer.

As for good customer service, the shop should have asked you to come into the store so that you could see the crack before it was condemed.

That is how it was phrased. Essentially “I’m going to have to condemn one of the tanks, but I need you to look at it before I do that.”

 

[rhwestfall]

For unusual cases we brought in a third person and/or contacted the manufacturer.

Very nice! The dick who did my re-quals at the first 5-year interval condemned my Worthington LP85 that had a total of a half dozen fills to rated capacity. He blew the test, and destroyed my tank. No interaction at all. It is truly apparent he did not follow the procedure to let it stabilize in the round-out process. My loss.... not a thing I can do about it. sucked....

 

[grf88]

I am of the same opinion that it is highly unlikely that a steel tank has a crack in the threads. Is it possible they are looking at the line that can be formed by the threading tap when it is reversed. I would certainly get a second opinion before the tank gets condemned.