20 year shelf life for Aluminum dive cylinders

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TALES of how florida delt with al tanks, al bad alloy, ins policy regs, al parinoia, refusal to accept other shiops vis stickers, requireing unmandated eddie tests at the time were the reasons i bought my steel tanks to begin with. With cave fills being common in the fla industry, ( i am not bashing fla) who knows whether the al tank has been routinly been fillid to +30% or more. and after all , from somes prespective, why should the al divers be held back from diving like th big boy's just becaue they dive with lower cost al tanks. I have to admit that shops have no idea what they are filling when a customer brings in thier own tank. I am not saying that to start a debate on whether cave fills ore ok or not, it is just a fact that the practice is in play when discussing vis and hydros and shop policies. When i was researching my tank buy, i early decided to never own a luxfer tank. not because it was a good or bad tank but for the reaction of some shops the might have problems with the luxfer history and a one rule policy to deal with it.

I too have a psi cert, my training was that we do not look to reject a tank but to prove a reason to pass a tank. Any border line problems were to be a pass and not a fail if not sent out for a second opinion. also things like a pit that is .060 is a pass and not a fail, that the < or = to .060 was ok because the progresion of damage would not endanger the tanks reliabiiity in the next 1 year's time. A crack is different as the depth may not be able to determine. each inspector is on thier own to make the interpretaiton of the damage. All this being fine untill a customer go's to kinkos to have bumper stickers that copy inspection stickers and slap on thier own tank to avoid paying the 15 bucks to have it legitimately vis'd. Now you have perhaps 5 years of fake stickers on a tank with never a valve removed being cave filled. I must admit that i dont blame many of the shops for thier policies. I also know that the majority of the fill stations do not have qualified hasmat trained fillers doing the work. I suspect the fla does not fall into that catagory to much. They are given a minimum set of criteria to check for. hydro vis and psi to get a fill. Most if checked at all look for only the vis sticker and get a 2 minute fill to 3k and out the door they go. lp;s hp's are all the same. In fairness i will say that < half the time when i bring a tank into a out of area shop they actually look over the tank before accepting it for refilling. There are both good and bad shops on the playing field. I will say that when filling to proper psi at the prescribed rates, most likely little should go wrong. but local policies are not made for those who comply, it is for protection from those who dont comply. A third party recently bought a couople of dozen tanks from anclosing shop and when removing the valves found 5 tanks with deep cracks in them, The selling shop had no qualifying inspectors or fill operators. so i know personally that problem fill shops exist.

If i go to fla and have a shop in mind to work out of i call to see what thier policies are before bringing my own tanks. IF its no fills whith out thier vis sticker i go somewhere else. When i get there i often ask to see thier fill operation. I have never been turned down.

Sorry i guess enough said on this off topic aspect of the op's question on 20 year shelf life.
 
I doubt he gets repeat customers any year. They wear it, hope to never need it, and if they ever do ride out of an avalanche with one, I have to wonder how many go right back out. :eek:

I know 2 people that have inflated them. Both were able to outrun the avalanche on their snowmobiles, or at least get out of the way. They were both out the next weekend.
 
I know 2 people that have inflated them. Both were able to outrun the avalanche on their snowmobiles, or at least get out of the way. They were both out the next weekend.
Now if they'd buried their snowmobiles and road out the avalanche on the bags, it might have been different. Bet they keep wearing them.
 
After 20 years, it makes more sense to replace the tank and valve than to hydro and VIP it.

If you figure out the cost of hydro and VIP against getting a brand new tank and valve, you are better off replacing an old tank.

If your tank fails, you just wasted your money.

Any tank that was made before 1990 should be scrutinized.

If you put your money into a new tank instead of a hydro & VIP, then you have a Brand New Tank instead of a flower box.Older anything is almost always harder to work on and takes special care....

I am one of those dive shops that will not fill a pre-1990 tank.

Here's the issue as I see it. You bring in a tank for VIP/Hydro. We perform the VIP/Hydro/EDDY test and everything checks out just fine. According to my PSI training, just because there isn't a failure point right now, doesn't mean that the issue won't/can't develop 3 weeks or 3 months from now. So, you passed EDDY, but the issue starts developing prior to reaching your next VIP.

awap, the nature of the alloy is how this issue differs from other tanks.

Beaverdiver and Superlyte27, just to be perfectly clear on your shop's policy:

Do you provide fills for properly tested and inspected steel tanks that were made before 1990?

Do you provide fills for properly tested and inspected Catalina aluminum tanks that were made before 1990?
 
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Here is a pretty good list of AL 6351 tanks from List of Scuba Tanks Made From 6351-T6 Alloy Question: Are the tanks marked with 6498, 7042, 8107, 8364, 8422, 7235, 8023, 8115 marked with one of those numbers instead of 6351 even tho they contain the hazardous alloy? (I see some reason for a blanket policy of no pre-1990 tanks!)
THE LIST
Several people have said that there is no list of tanks made from the 6351-T6 alloy. This is not exactly correct. While it is true that there doesn't seem to be a nice cross referenced list of serial numbers available to the public, there is a "list" sufficient for most people to figure out if their tanks are made from the bad alloy. The following comes directly from the DOT Safety Alert Bulletin:


Here is "The List" of scuba tanks that the DOT says are most likely made from the 6351-T6 aluminum alloy:

  • All DOT-3AL tanks manufactured under one of the following exemptions or special permits: 6498, 7042, 8107, 8364, 8422
  • All composite cylinders manufactured under one of the following exemptions: 7235, 8023, 8115
  • All Walter Kidde DOT-3AL scuba tanks.
  • All Cliff Impact DOT-3AL scuba tanks made before July 1990.
  • All Luxfer 80.8 cu. ft. scuba tanks (S80.8) made before May 1987.
  • All Luxfer 72 and 100 cu. ft. scuba tanks (S72, S100) made before August 1987.
  • All Luxfer 80 cu. ft. scuba tanks (S80) made before January 1988.
  • All Luxfer 50 and 92 cu. ft. scuba tanks (S50, S92) made before April 1988.
  • All Luxfer 30 and 63 cu. ft scuba tanks (S30, S63) made before May 1988.
  • All Luxfer 40 cu. ft. scuba tanks (S40) made before June 1988.
  • All other scuba tanks made in the US before February 1990 (except Catalina).
  • All scuba tanks not made in the US.
Unless proven otherwise, all scuba tanks in the above list should be assumed as being made using the 6351-T6 alloy.


Note that many other types of cylinders (SCBA, Medical, Industrial, CO2, etc.) were also made from the 6351-T6 alloy. However, for brevity, only SCUBA type cylinders are listed above. See the DOT Safety Alert Bulletin for information on those.
Also, it should be noted that Catalina cylinders were NEVER made from the 6351-T6 alloy. They were made using alloy 6061-T6, which as of yet, has not been known to fail explosively. All of the manufacturers in the above list, except Walter Kidde, switched to the 6061-T6 alloy on the dates shown.
The DOT has not as of yet issued a recall of these tanks - only a safety alert. Essentially, if you own or use a scuba tank in the above list , you should consider it as being a time bomb waiting to explode. You should consider the tank unsafe until you learn for certain that it is made from the new alloy.

And an interesting excerpt from Fill Express -- FAQ About Filling Aluminum 6351-T6 SCUBA Cylinders
Why will you only fill 6351-T6 cylinders that Fill Express has inspected?
According to Luxfer, your 6351-T6 cylinders are safe for us to fill only "as long as your 6351-alloy scuba tank is properly inspected". The problem is some aluminum 6351-T6 SCUBA cylinders are NOT properly inspected, and therefore may be unsafe to fill because of SLC. According to Bill High, President of Professional Scuba Inspectors, Inc. (PSI) only about 10% of the people performing SCUBA cylinder inspections in the US are trained inspectors. Proper inspection of 6351-T6 alloy cylinders requires special tools and additional specialized training. Because we have no way of being certain the cylinder has been properly inspected, and because of the increased risk to our fill station operators, we choose to require all 6351-T6 alloy cylinders be inspected by our PSI trained staff before we will fill them.
 
Because you also have to provide a $0.25 rupture disk.
No, we have to put a new o-ring in the unit.

---------- Post added April 9th, 2012 at 11:03 AM ----------

I'm not that gullible. Avalanche bags? I'm guessing that is something used to rescue people in some way. If so I'd fill them for free as a public service. Seems immoral to charge that much for so little if it saves someone's life.
Sent from my DROID X2 using Tapatalk
The average person getting a fill has $10,000 - $20,000 in snowmobile gear or they use it for Heli Skiing, which costs 10,000 - $20,000 a week. They do not need charity. They probably give more to charity than our store grosses in a year.

We had one person give us a $10 tip after we spent the time to fill his 2 cu ft. 3000 PSI cylinder.

It is not the amount but the fill pressure and the time it takes that makes it worth the money.

After my 27 year old compressor went down after less than 3000 hours, I had to buy a new compressor. I invested in a Bauer. I have close to $20,000 in it. Instead of a new truck, I put money in a new compressor. My 1995 truck just hit 100,000 miles.

Unfortunately, it will probably be the last compressor that I buy, due to the reality it will probably out live me!

It cost me $26 to fill an 80 cu ft tank. We charge $20 for our clients. If we fill for commercial use, $52.

As far as the 20 year tank rule, we are very hesitant to fill tanks dated before 1990.

Jim, do you consider yourself to be a dive professional or just a diver that works out of his basement doing it for a hobby?
 
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Given the poor track record the scuba industry has on cylinder inspection and from a first hand report from someone who was doing everything right in regards to a 6351 cylinder but still had it crack while filling (not explode) I will fully respect any shop that chooses not to fill 6351 cylinder. Further I will further respect any shop that will fill them but only if they inspect them.

However, the no cylinders before 1990 is utter bovine excrement and IMHO is one of the most well known worst business practice in the industry.

1. The date came about because it is an easy date to remember, I.e being a new decade it is "easier" to remember than reading a one page summary of the actual affected cylinders.

2. Catalina cylinders have always used 6061. I have actually seen a couple of 1989 Catalina cylinders.

3. Cylinders were made from AL6351 in 1990. While WK and CI are uncommon they are out there. As such, there is the potential to still fill a 6351 cylinder!!!!!


So a shop giving the no cylinder before 1990 will not get my respect nor my business. As the utilization of 1990 date tells me multiple things, lack of attention to detail (i.e 1 above), unwilling to use reference material (1), turning away potential business (2), and finally speciously reasoning they are concerned with safety when in fact they are not (3).

Now if the shop is employing people or themselves are unwilling/unable to read the cylinder markings and within 1 minute determine the cylinder material I have to ask do you really want to rely upon them for something more complicated like fixing your regulator??? Which we are know is "life" support and should only be worked on by a "professional" What other "short" cuts might the store "professionals" be doing all in the name of "safety" or "convenience"? Is that really a customer oriented business one wants to patronage??? Are they calibrating their gauges on regular basis so you get a full fill (assuming they are not hot filling)? Or replacing filters on their compressor? Or doing other routine maintenance/inspections?

One of the last times I was in FL we called a shop about doing a couple of dives with them. We signed up and gave a deposit for the next day. When we arrived the next day and noticed that they had a nice little sign that said "NO FILLING OF CYLINDERS MADE BEFORE 1990" about 45 minutes later we left, never dove cause their boat was not running. Hmm, I wonder if they could not be bothered with details about their boat like they were with cylinders???
 
Given the poor track record the scuba industry has on cylinder inspection and from a first hand report from someone who was doing everything right in regards to a 6351 cylinder but still had it crack while filling (not explode) I will fully respect any shop that chooses not to fill 6351 cylinder. Further I will further respect any shop that will fill them but only if they inspect them.

However, the no cylinders before 1990 is utter bovine excrement and IMHO is one of the most well known worst business practice in the industry.

1. The date came about because it is an easy date to remember, I.e being a new decade it is "easier" to remember than reading a one page summary of the actual affected cylinders.

2. Catalina cylinders have always used 6061. I have actually seen a couple of 1989 Catalina cylinders.

3. Cylinders were made from AL6351 in 1990. While WK and CI are uncommon they are out there. As such, there is the potential to still fill a 6351 cylinder!!!!!


So a shop giving the no cylinder before 1990 will not get my respect nor my business. As the utilization of 1990 date tells me multiple things, lack of attention to detail (i.e 1 above), unwilling to use reference material (1), turning away potential business (2), and finally speciously reasoning they are concerned with safety when in fact they are not (3).

Now if the shop is employing people or themselves are unwilling/unable to read the cylinder markings and within 1 minute determine the cylinder material I have to ask do you really want to rely upon them for something more complicated like fixing your regulator??? Which we are know is "life" support and should only be worked on by a "professional" What other "short" cuts might the store "professionals" be doing all in the name of "safety" or "convenience"? Is that really a customer oriented business one wants to patronage??? Are they calibrating their gauges on regular basis so you get a full fill (assuming they are not hot filling)? Or replacing filters on their compressor? Or doing other routine maintenance/inspections?

One of the last times I was in FL we called a shop about doing a couple of dives with them. We signed up and gave a deposit for the next day. When we arrived the next day and noticed that they had a nice little sign that said "NO FILLING OF CYLINDERS MADE BEFORE 1990" about 45 minutes later we left, never dove cause their boat was not running. Hmm, I wonder if they could not be bothered with details about their boat like they were with cylinders???


The subject of this thread is 20 year shelf life not whether 6351 cylinders should be filled. There are a few cylinder made before 1990 that use 6061-T6 aluminum but I would still support a dive shop that refused to fill pre '90 tanks. I would run from any shop that tried to claim 20 year shelf life on cylinders because I think we can all agree that is utter BS.
 
The subject of this thread is 20 year shelf life not whether 6351 cylinders should be filled.

You are correct a bit of thread drift but it still all goes back to some in the dive industry making crap up.

There are a few cylinder made before 1990 that use 6061-T6 aluminum but I would still support a dive shop that refused to fill pre '90 tanks.

Is that a pre 1990 for all cylinders or just the aluminum ones? The shop sign I noted was for ALL cylinders steel and aluminum alike.

I would run from any shop that tried to claim 20 year shelf life on cylinders because I think we can all agree that is utter BS.

I think we can but ...
 
You are correct a bit of thread drift but it still all goes back to some in the dive industry making crap up.



Is that a pre 1990 for all cylinders or just the aluminum ones? The shop sign I noted was for ALL cylinders steel and aluminum alike.



I think we can but ...

Good thing I own my compressor. I recently accidentally filled my steel lp 72 (2250psi rated) to 3500psi. It was built in 1960.
 
https://www.shearwater.com/products/swift/

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