OP
Ob1Stogie
Guest
Tanks still had 800 psi when I took them in. They were stored upright in the garage. All my fills were from local dive shops and not boats or Mexico where the air might not be as dry.
Moral of the story, hydro your tanks even if you don't plan to dive
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captain
Contributor
A tank can not be destroyed or the markings stamped over without the owners permission. The reason being private ownership of a tank does not fall under jurisdiction of DOT. If you own the tank, fill it with your own compressor and transport it in your personal vehicle it does not have to be in current hydro. You do not break any laws or regulations by doing so. DOT regulation only apply to commercial entities. They should have returned the tanks to you just as you gave them to them. I have a friend that had the same thing happened to him. The shop ended up buying him two tanks. If you would like to hear his story PM me and I will put you in contact with him.
langs15
Guest
What would happen if they had been filled or half way filled or so and standing right up?
OP
Ob1Stogie
Guest
If I wasnt able to buy two faber 95's from friends who don't dive any more (for $50 each), I might persue the hydro place.
With the price of tanks it isn't even really worth the energy to get them retested. . . I mean not sure about you but if one person says the tank is unsafe thats enough for me. . . don't need to lose a hand or my life to save a few bucks!!!
Get over it, or better still, buy your own compressor and stand beside the tanks as you fill hot fill them to 3500 psi. It's unlikely that they'll blow. Afterall they're only 20 plus years old and full of rust. What do you think the rust is? It's the tank falling apart.
You didn't miss them for 10 years. Get some new ones.
Serious question. Do you know what fails a hydro and why? A tank can pass a visual yet fail a hydro.And conversely a tank can fail a hydro and pass a visual.
You didn't miss them for 10 years. Get some new ones.
Serious question. Do you know what fails a hydro and why? A tank can pass a visual yet fail a hydro.And conversely a tank can fail a hydro and pass a visual.
captain
Contributor
A steel tank is unlikely to fail a hydro unless it has been in a fire hot enough to change the propertied of the steel or it has been grossly overpressured many times which is not likely. This would have to be at a pressure even beyond hydro test pressure for hundreds if not thousands of times. A hydro test determines if the steel has lost its elasticity. Age does not cause steel to lose it elasticity.The hydro facility I use (not an LDS) told me that a steel breathing air tank is failed for internal rust 99.99% of the time. The reason being rust particules could clog the valve or regulator. Years ago I bought a used steel tank, when I took the valve off I poured out about a half gallon of water. It looked like the surface of the moon inside. I figured it was toast but I acid cleaned all the rust out and it passed hydro.
captain
Contributor
spiro:
Many old steel 72's are being failed for no good reason because of ignorance. It has been worse since the sustain load cracking issue in aluminum tanks has everyone paranoid everytime they see a tank more than 10 years old. I have several steel 72's pushing 50 years old. They will out live me
I agree. Rust is the issue causing most steel tank condemnations but a pit serious enough to fail the tank is only going to occur if you had standing water (droplet or otherwise) in the tank or if enough flash rust accumulated to attract and hold moisture in one spot.
I think what are often viewed as "pits" in steel tanks are in fact just spots of flash rust near the center of the base of the tank that are not easy to remove by conventional tumbling where the tank is essentially level. If you are able to tumble them on about a 30-45 degree angle and are willing to tumble them 8 hours or so, the rust spot will often be removed and allow you to observe that no serious pit is actually present under the rust.
The issue with a pit is that it could become a stress riser and cause the tank to fail in that paticular location. But, like anything else on a tank, it requires a fairly substantial depth for this to be a factor. In fact I have a couple of Faber tanks that actually have that looks like a couple I's or a 1's stamped inside on the base of the tank (I have no idea why). But the feeling at VIP and Hydro tests has always been that the the same criteria of being no deeper than the letters and numbers stamped on the shoulder applies and they are not problematic. Now..if they were in the side wall it would be a different story.
Due to the generally thinner metal as well as increased stress in the side walls, you do not want to store tanks lying on their sides. If that occurs any moisture in the tank will accumulate on the "bottom" side of the tank and potentially cause pits in the thinner and more critical side wall which should rightly make an inspector nervous enough to condemn the tank.
I do feel that some shops have a chicken little approach to filling any old tank and get safety conscious to the point of paranoia. The fact is, statistically or otherwise, filling a tank, (even the infamous 6351T-6 alloy aluminum tanks) is far safer than the drive you made to work that morning, but no one is calling for manadatory condmening of cars - even cars older than 10 years that may not have even had a recent vehicle safety inspection.
I think what are often viewed as "pits" in steel tanks are in fact just spots of flash rust near the center of the base of the tank that are not easy to remove by conventional tumbling where the tank is essentially level. If you are able to tumble them on about a 30-45 degree angle and are willing to tumble them 8 hours or so, the rust spot will often be removed and allow you to observe that no serious pit is actually present under the rust.
The issue with a pit is that it could become a stress riser and cause the tank to fail in that paticular location. But, like anything else on a tank, it requires a fairly substantial depth for this to be a factor. In fact I have a couple of Faber tanks that actually have that looks like a couple I's or a 1's stamped inside on the base of the tank (I have no idea why). But the feeling at VIP and Hydro tests has always been that the the same criteria of being no deeper than the letters and numbers stamped on the shoulder applies and they are not problematic. Now..if they were in the side wall it would be a different story.
Due to the generally thinner metal as well as increased stress in the side walls, you do not want to store tanks lying on their sides. If that occurs any moisture in the tank will accumulate on the "bottom" side of the tank and potentially cause pits in the thinner and more critical side wall which should rightly make an inspector nervous enough to condemn the tank.
I do feel that some shops have a chicken little approach to filling any old tank and get safety conscious to the point of paranoia. The fact is, statistically or otherwise, filling a tank, (even the infamous 6351T-6 alloy aluminum tanks) is far safer than the drive you made to work that morning, but no one is calling for manadatory condmening of cars - even cars older than 10 years that may not have even had a recent vehicle safety inspection.
captain:
Not true. I have failed a number of steel tanks because the permanent expansion numbers exceed spec. Steel tanks fail hydro, aluminum tanks fail visual. The only steel tanks I've failed are the old 72s with the coated interior where the paint is all bubbled and nasty which tells me there is significant, unchecked corrosion in there and because I can't see it and measure it, the tank must be condemned.
Rachel
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