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Prouty33
08-05-2007, 15:15
I've heard that steel tanks can last a really long time if properly maintained, how long is "a long time"? A family friend offered to give me a pair of steel tanks that have been in storage for around 20 years. He said he bought them new, and they were only hydroed the first time. He dove them a few years and gave up diving, and have been sitting in his basement since, so I'm going to guess they were manufactured around 1980? Assuming I take a look at them and they look fine, will these tanks pass hydro? How long could I expect them to last if they did?

WaterRat
08-05-2007, 15:19
There are old steel 72's still in service from the 70's. Rust is the main enemy of steel tanks. If they were stored with air in them and water never got in them, I bet they're fine. Send them in for hydro.

Ron

DirtyWaterIL
08-05-2007, 15:27
If the tanks are properly maintained and cared for they will proably last longer than you do. take them into your lds and ask for a vis on them befor eyou send them to hydro. if they do a visual inspection they will be able to spot any cracks or serious rust. If there is minnor rust which is proabbly after that long they may be able to put it on a tumbler and get rid of it. Also after sitting for that long i'm sure all the seals in the valves are completely rotted so you will need to have those rebuilt as well.

texdiveguy
08-05-2007, 15:37
I have a steel 72 still in service from 1971.

cummings66
08-05-2007, 22:18
I've got a steel HP100 from 1984 and always passes.

BSea
08-05-2007, 22:44
I have a steel 72 tank from 67 or 68. It's getting filled or I'd know for sure the origianla date. I have some double 38's from 68. If you keep water out of them & some pressure on them, they should last as long as you will dive.

But, there are some dive shops that refuse to fill tanks past a certain age. I guess they have that right, but I'd rather have a steel tank from the 60's than an aluminum tank from the early eighty's.

But that's just me.

ScaredSilly
08-07-2007, 16:01
Seems I have heard of steel banks with cylinders that are getting to be near 100 years old. I think the ones in our program are from the 40s. A few folks are diving steels from the late 50s.

If the cylinders in question have some air in them and never had any water good chance they will be okay. Take them in for a visual and hydro.

Also if the original hydro has a plus rating (12/81+) make sure you ask for the hydro tester to requalify them at the plus rating. This will maintain their 10% over fill.

divinginn
08-07-2007, 19:00
i have two old steel 72s.one is a 66 model and the other is a 73,as long as they stay dry inside with pressure on them,they will last pretty much forever,they are designed to last ten thousand cycles.

turtle_guy
08-10-2007, 00:43
As far as i know they will last until you decide to either quit diving or are somehow rendered unable.

MxDiver
08-12-2007, 18:54
A couple of days ago my instructor gave me a couple of steel 72s for free. They need the visual and hydro done, when I opened the valve some air came out, which I think is good by what I read in this post.
They have a single air outlet on the center and a single band. If they pass the test I’m planning on getting double bands so they fit my BCD (Zeagle brigade with a manta wing) and using them to get the feel of diving with doubles before my advanced nitrox class.

Hollywood703
08-22-2007, 10:57
Generally the tank with the plus rating Can not be recertified as a + rating, or is my understanding shouldnt be, as some are doing. I'll have to break out my DOT book, but i thought thats what i read, as it was only valid on the intial Hydro...outisde of that is a violation.

subsur
08-22-2007, 11:24
they can last decades as long as you properly maintain them - meaning no water gets inside and you store them with pressurized air.

mountaindiver
08-22-2007, 12:46
I have a steel tank still in service from '63, well maintained it will last!

BSea
08-22-2007, 12:49
Generally the tank with the plus rating Can not be recertified as a + rating, or is my understanding shouldnt be, as some are doing. I'll have to break out my DOT book, but i thought thats what i read, as it was only valid on the intial Hydro...outisde of that is a violation.
I don't think this is true. They can be recertified at the higher pressure. It's just that the places that do hydro's generally don't test at the + pressure. If you have a steel tank with a + rating, be sure and specify that you want the higher test pressure. At least, that's the way it was explained to me.

I just checked one of my tanks that dates from the 60's. It has 2 + ratings with the last 1 being in 1980. And 3 or 4 dates before & after that don't have the +.

Hollywood703
08-22-2007, 13:28
ok, i was talking about aluminum tanks.....I have never had a + steel tank.....I was told by 2 different places that an aluminum tank can not be re-certed for + after the initial hydro....I have no experience with steel and + tanks

Hollywood703
08-22-2007, 13:42
I just got off the phone with the local hydro guy(who does all the fire departments tanks)....He said most steel can be + rated recert, they have a list of tanks that can be + rated after the original + rating....(based on their elasticity rating) however not all are eligible.....also he said they can not do aluminum tank recerts for + rating, even if it had one to start.

BSea
08-22-2007, 14:24
I just got off the phone with the local hydro guy(who does all the fire departments tanks)....He said most steel can be + rated recert, they have a list of tanks that can be + rated after the original + rating....(based on their elasticity rating) however not all are eligible.....also he said they can not do aluminum tank recerts for + rating, even if it had one to start.
I'd be interested to know what tanks aren't eligible. Plus, I never new there were aluminum tanks that had a + rating (file this under the "You learn something new everyday" rule). But except for my pony, I have all steel.

Peter_V
08-26-2007, 03:27
If the tanks are in good shape, and you take care of them, your grandkids will be able to use them when they are teaching their kids how to dive.

Krakenn
08-26-2007, 05:19
dont u guys have to hydro each year?

Kraks

terrillja
08-26-2007, 09:58
dont u guys have to hydro each year?

Kraks

Have to Viz every year, hydro every 5.

in_cavediver
08-26-2007, 10:09
I'll add only one other caveat to this discussion. Some of the older exemption tanks that are still around have not had thier exemption re-filed and are not elgible for hydro recert. I belive most of these are Al tanks though.

As for + rated tanks, from the DOT regs I have, so long as the paperwork is good, any 3AA steel tank can be certed to the + rating, even if it lost it or never had it. Many of the exemption tanks (think HP) are not eligible for the + rating due the the exemption paperwork they were filed with.

And lifespan. At work, we have a K bottle of Argon with its first hydro date in the 30's. 70+ years and going strong.

willardj
08-26-2007, 16:38
I have 3-72's the single is a 69 and have a set of doubled up that are both 71's. still going strong.

Krakenn
08-27-2007, 06:24
Has anyone done any research on accidents from old bottles?

Kraks

DennisW
08-27-2007, 08:53
I am going to inspect a tank this weekend that was built in March of 1955. Same age I am.

Kingpatzer
08-27-2007, 10:35
I have a buddy who found a steel tank in the back of a car in a junk yard. The tank was made in the late 1940's. He had it cleaned and checked and it works just fine, he uses it all the time. It had sat about 20 years since it's last inspection when he found it.

BSea
08-27-2007, 10:42
I am going to inspect a tank this weekend that was built in March of 1955. Same age I am.
That is really cool. I have 2 double hose regs that are 1958 vintage, almost as old as I am (I'm also 1955).