rubberduck
Guest
Is there any age restrictions to a AL tank? Can a tank fail hydro on age alone if it is still in good condition?
Tank hydro question
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Not yet.rubberduck:
Rick
Hydrostatic testing is a very specific measurement of tank expansion. There is no "opinion" about it. Either a tank passes, or it fails.
There is a visual that's performed prior to hydro that is more likely (in my experience) to fail a tank than the actual hydro itself and tank age is often a factor there, but not because of the age of the tank, per se, but because the alloy that older tanks were made from are more likely to develop neck cracks.
Is that too much information?
Rachel
There is a visual that's performed prior to hydro that is more likely (in my experience) to fail a tank than the actual hydro itself and tank age is often a factor there, but not because of the age of the tank, per se, but because the alloy that older tanks were made from are more likely to develop neck cracks.
Is that too much information?
Rachel
Age has nothing to do with the passing, or failure of a tank, If it is visibaly pitted, it may fail, if it is an AL tank, and there is a gough of more than a 1/6 of an inch, it will fail. Other than the insides being pitted, or neck cracks,, They will last longer than you may think. I just sold a super 80 to a friend, that is 20 years old, and still rocking on!
mike_s
Contributor
rubberduck:
Like the others said... no age restrictions.
There are people out there still using tanks from the 1960's and 1970's with nothing wrong with them.
The only "issue" with older tanks is that some Aluminum 80's made before 1989 or 1988 were made with a different aluminum allow that more precautions need to be taken with on visuals. Otherwise they are perfectly safe. However, some shops won't fill them. Why? because not all visuals are done to the same standards and by truely qualified people. That's about the only issue with age on tanks and that's not really an age thing but an aluminum alloy thing.
There have been a few other tanks that have had recalls, etc... like some OMS tanks and I'm sure some others, but for the most part you don't have anything to worry about.
RonFrank
Contributor
rubberduck:
If you are considering an older tank, there was a batch of AL80 I believe made by Luxfar in the 70's or 80's that have been prone for issues.
It's been too long since I was tank shopping for me to remember the specifics, but if you are looking at older AL80's, make sure you get the poop on what brand and models had issues over the years.
A hydro is pass/fail, and tank age is not a consideration. Ironically you can run into issues with the LDS vis even after the hydro inspection (which also includes a vis). To add insult to injury the LDS's often charge more for a vis than you would pay for a hydro at the facilities that actually DO hydro's (most LDS's do NOT hydro tanks, they send them out).
After much research on the issue I have come to the conculsion that one is better off taking a tank into the LDS for hydro/vis as generally a hydro may run $10-15 via the facility that actually does it, and the LDS will charge you $30 for a hydro/VIS, and $20+ for a Vis alone.
More info than maybe you wanted
XS Scuba
Contributor
Hi rubberduck:
In general, all of the above replies are correct, though there is an exception. The likelihood that you would come across one is about zero. The exception is the Luxfer Limited cylinders. These are composite cylinders, that is they're manufactured with more then one material. These cylinders are manufactured like other aluminum scuba cylinders, then the side walls are "hoop wrapped" with fiberglass and resin for increased strength. These have a working pressure of 4350 psi. The interesting thing is, these cylinders require retesting by hydro every 3 years, not 5 and after 15 years these cylinders are to be removed from service. Once 15 years old, these cylinders will make a fine door stop, but not much else. The Luxfer Limited cylinders have only been available for about three years, so there is no chance of running across a "dead" one yet. You can find more information at this link (part number ALW106) http://xsscuba.com/tank_alum_specs.html
In general, all of the above replies are correct, though there is an exception. The likelihood that you would come across one is about zero. The exception is the Luxfer Limited cylinders. These are composite cylinders, that is they're manufactured with more then one material. These cylinders are manufactured like other aluminum scuba cylinders, then the side walls are "hoop wrapped" with fiberglass and resin for increased strength. These have a working pressure of 4350 psi. The interesting thing is, these cylinders require retesting by hydro every 3 years, not 5 and after 15 years these cylinders are to be removed from service. Once 15 years old, these cylinders will make a fine door stop, but not much else. The Luxfer Limited cylinders have only been available for about three years, so there is no chance of running across a "dead" one yet. You can find more information at this link (part number ALW106) http://xsscuba.com/tank_alum_specs.html
rubberduck:
Took the Visual Inspection course just the other day and was told....
* (These are DOT standards - not necessarily Canada or elsewhere)
1. all round bottom aluminum cylinders are illegal. Cylinders used to be extruded and the bottom hole plugged. They are rarely seen anymore but cannot be passed.
2. tanks marked with SP6576 with a working pressure of 2700 psi(manufacturer Kaiser) used magnesium zinc alloy not suitable for high pressure. No longer legal
3. tanks marked with SP6688 (manufacturer Norris) are illegal because they are not protected by manufacturer's liability. Recognizable by elongated / stretched shoulder.
Remember these are USA standards. Luxfer's prior to 88 may have a higher rate of neck cracking so some shops may chose not to inspect them any longer. Owners should take extra care and make sure your inspector is qualified.
* (These are DOT standards - not necessarily Canada or elsewhere)
1. all round bottom aluminum cylinders are illegal. Cylinders used to be extruded and the bottom hole plugged. They are rarely seen anymore but cannot be passed.
2. tanks marked with SP6576 with a working pressure of 2700 psi(manufacturer Kaiser) used magnesium zinc alloy not suitable for high pressure. No longer legal
3. tanks marked with SP6688 (manufacturer Norris) are illegal because they are not protected by manufacturer's liability. Recognizable by elongated / stretched shoulder.
Remember these are USA standards. Luxfer's prior to 88 may have a higher rate of neck cracking so some shops may chose not to inspect them any longer. Owners should take extra care and make sure your inspector is qualified.
OP
rubberduck
Guest
Thanks for the good advice everyone. I'll have to keep an eye out for the mentioned problems.
I'm totally intrigued by this new Luxfer tank...
The biggest issue I see is actually getting it filled to rated pressure since most fill stations don't even bank enough pressure to properly top these off.
Do you have any experience with these tanks and what is your general impression?
Rachel
The biggest issue I see is actually getting it filled to rated pressure since most fill stations don't even bank enough pressure to properly top these off.
Do you have any experience with these tanks and what is your general impression?
Rachel
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