Old steels denied fills due to store "policy"

[Bob DBF]

The assertion was that steel scuba cylinders as long as they pass Vis and hydro are not life limited. I disagreed especially with long life items. Would I have a 50 year old cylinder, pass it onto my kids and tell them it'll be good for another 50 years? No way!

Could be that you are not dealing with DOT 3AA tanks, or DOT tanks period, and the SCUBA tank standards are different where you are. The treatment of the tanks, I feel, is probably the major difference. In the early days of SCUBA in the US, a lot of tanks were lost to poor procedures, poor treatment, and neglect. Over time, fill procedures, the VIP system, and divers awareness of using and maintaining tanks, have made finding an inch of rusty water in the bottom of a tank quite rare.


Edit: yes I am hoping to pass my 50+ year old tank on to my daughter for another 50. Hoping her kids take up diving to continue the use.



Bob

 

[Diving Dubai]

Could be that you are not dealing with DOT 3AA tanks, or DOT tanks period, and the SCUBA tank standards are different where you are

No, we have a mix. All Ali are all DOT 3000 with burst discs, where as Steels (generally privately owned) are all EU/UK 3442 generally Faber and no burst discs. Our inspection procedures all mimic the US with annual Vis and 5 yr Hydro

 

[Diving Dubai]

If you owned a 50 year old steel cylinder that passed hydro and vis last month would you replace it due to age or dive it? I mean it could fail the next hydro, sure. But for now.. it's good, right?

There are plenty of folks in the cave country area that have been massively overfilling steel tanks for decades. Even those abused steels aren't catastrophically failing. Clearly, you know more about metallurgy than the nothing that I know. That said, the evidence doesn't seem to support properly maintained steel tanks having a finite lifespan. It doesn't even seem to support abused steel tanks having a finite lifespan.

Fair points - although I've never agreed with Cave fills - but each to their own. That horse died years ago - painfully

No I wouldn't even consider owning a 50yr old tank With my current thoughts it'd been retired at 30-40 years even though they're not heavily used (less than 5 fills a month each tank)

 

[txgoose]

With my current thoughts it'd been retired at 30-40 years even though they're not heavily used (less than 5 fills a month each tank)

I realize that it can’t be conveyed well in typed text on a forum, but I swear that I mean this as a tease that one friend would give another:

You do recognize that at 40 years you would have already doubled the limit suggested by fullytek and (at least one fill jockey at) Force E?

 

[Diver below 83]

About Us - Aquatic Ventures Best Scuba Classes in Florida

Aquatic ventures is located in Ft Lauderdale and will handle all your tank needs regardless of age. If they pass vis and hydro they will fill them for you.

They also do Vis and Hydro in case your old or new tank needs it. They don’t use a secondary company either so everything is all one stop shop and go.

 

[markmud]

Fair points - although I've never agreed with Cave fills - but each to their own. That horse died years ago - painfully

No I wouldn't even consider owning a 50yr old tank With my current thoughts it'd been retired at 30-40 years even though they're not heavily used (less than 5 fills a month each tank)

Hi DD,

Steel, without corrosive agents, or numerous high stress cycles, does not deteriorate. The molecular structure does not change. It is a stable material.

I had a steel PST 72 that my brother bought in 1972. He used it 3 or 4 times (literally). It sat in a garage in Coronado CA for decades. It had about 500 psi in it. The outside looked fresh, the inside looked new. At almost 40 years old, it passed hydro and vis. We installed a modern valve on it. The steel in that tank had not changed, on a molecular level, in the decades that it sat in a cool garage.

I believe a friend is still using that tank.

At nearly fifty years old, if that tank appeared inside and out, as it did 10 years ago, and had a current hydro/vis, I would fill it--and dive it.

Without a second thought!

As always,
markm

 

[BRT]

There are no faults. And you won't' find record of failure unless there's been a serious incident - even then they're hard to come by.

The assertion was that steel scuba cylinders as long as they pass Vis and hydro are not life limited. I disagreed especially with long life items. Would I have a 50 year old cylinder, pass it onto my kids and tell them it'll be good for another 50 years? No way!

And yet it probably is good for another 50.

 

[rjack321]

I have had numerous pre-WW2 era steel oxygen cylinders in my garage, 1920s, 1930s manufacturing dates. They have star ratings (10yr hydro cycles) and even though they were made before USDOT even existed as an agency they are perfectly valid and considered "safe" and legal for use.

This thread is full of emotional drama about safety. I am sympathetic to shops denying fills to ali 6351 cylinders. That is a valid debate and there are good reasons why PSI and other's assessments of "safe" is not safe enough or too anxiety producing to be worth it. But steel and ali 6061 cylinders in hydro and vis and not even subject to eddy current testing? Steel getting old? There are 100+ year old steel ships and bridges and skyscrapers still in use too, with arguably less exhaustive structural examinations than hydros and visuals.

 

[Rred]

If you are trying to measure the strength or condition of a steel part (including a tank) simply by its age...That's about as useful as asking how long is a piece of string.

If the US DOT asks for 100,000 pressure cycles on a tank, consider. That's going to get possibly 1000 cycles per year in daily twin-tank diving, i.e. commercial use. A hundred years of use? And for the typical recreational diver doing less than 50 dives a year? How many years is that?

So just saying "that tank is too old" is BS. That's a judgement call from someone who just doesn't want to be bothered with looking at the actual condition, and would rather rent or sell new gear. Like the local dive shops, who insist on VIPing freshly hydro'd tanks, and totally ignoring the fact that every hydro begins with a DOT-qualified VIP, so if you don't trust THAT was done properly...you really shouldn't trust the hydro, either.

 

[Bob DBF]

Like the local dive shops, who insist on VIPing freshly hydro'd tanks, and totally ignoring the fact that every hydro begins with a DOT-qualified VIP...

It could have just been where I was filling tanks, but when the VIP program started, a shop would look at the hydro stamp, and if it was in the first year after that date, the sticker was not required. One year after the hydro date the sticker was required. Sometime later the sticker was required at the time of hydro.


Bob