Dive tank permanent expiration?

[tracydr]

If they are 6351 alloy tanks they can still be used if they have been eddy tested. Even if your instructor is as experienced as he says you should know that he makes far more money selling gear then he dose teaching. Just out of curiosity next time you go to class look at the dates of the tanks they are providing.

---------- Post added July 13th, 2013 at 07:45 AM ----------



I have gotten fills from hydro facilities all over the country when I am working in remote areas where there are no dive shops, that is how I came to start using them in the first place. They can fill your tanks with air every bit as good as your LDS but they do not do nitrox. The LDS will tell you that these places are only good for fire extinguishers but they do not tell you that they take your tanks there to be inspected. I would put more faith in a DOT regulated facility then a LDS that makes up its own rules based on how they feel and what will help them sell more equipment. To be fair most LDS will fill properly tested tanks but the ones that do not give the rest of the industry a bad name.

In Lawton,OK, the place everyone used to get fills was at the fire station. Then, they stopped filling and you had to get fills in Duncan (50 miles away east)to dive the lake 15 miles NW. I used to live 5 miles from the lake so the dive shop owner would bring swap my tanks out for me on the way to the lake to teach. He also brought the different fire shops in the area their tanks, since nobody apparently had a compressor, except maybe Ft.Sill.
Now, I understand that shop is closed but I believe he may have opened something back up in Lawton, which is good. I haven't been back there in 9 years.
Anybody in that area, Lake Lawtonka has a really nice area to dive on the Ft.Sill side of the lake by the dam, just before Medicine Park. Clear water with an interesting rocky shore, fun to explore with lots of bass. You can go really deep with lights,dry suit,etc.

 

[Superlyte27]

Steel 72's are a different animal than LP85's 95's 104's and 121's. Cut any of those tanks in half and compare them to a 72, you'll see the difference.

I said something "very funny"? Did people laugh? I don't remember it. It's so rare that I say anything even mildly funny.[/QUOTE

If they are all built to 3AA specification you can't make a comparison on strength on what the wall thickness is. The larger the diameter of the tank the thicker the walls have to be to contain the same pressure. A tank 3 feet in diameter might have a wall thickness it 2 inches. That is no indication that the wall thickness on a 72 is not thick enough. It's called mechanical engineering.

Ehh, you might be right.
Here's what I do know from a vast amount of experience in the overfill capital of the world...
Lp85's 95's and 104's will handle decades of 4000psi fills. 72's will NOT.

 

[chrpai]

Here's what I do know from a vast amount of experience in the overfill capital of the world...
Lp85's 95's and 104's will handle decades of 4000psi fills. 72's will NOT.

How about 3000?

 

[Superlyte27]

Well, to be honest, there's two different fill pressures for the 72. Some of them were (and I'm going by faulty memory) 2250 and some of them were 2400. If I remember correctly, one of them were very very bad on hydro day, and some were just kind of bad. I'm assuming the 2250's were the ones we didn't overfill at all.

What I do know is, I'm skittish filling 72's beyond rated pressure. Maybe it's just sillyness, but I'm okay with that too.

 

[Scared Silly]

I can guarantee you that's why we do it. We found no matter what employee we hired, we can't get them to check the chart to see if the tank is on the list. And frankly the list also states that tank X, Y, or Z might be of the bad alloy. So, we simply engaged the blanket policy on the tanks [No Al cylinders made in 1989 or earlier, i.e. before 1990]. And as I said before, we're okay with it.

I find the above statement interesting. For a couple reasons:

Notice No. 94-7; Safety Advisory; High Pressure Aluminum Seamless and Aluminum Composite Hoop-Wrapped Cylinders

According to Luxfer USA data, the following types of cylinders stamped as manufactured by Luxfer USA
before the dates indicated below likely are made from alloy 6351-T6.All Walter Kidde DOT-3AL cylinders, of which production ceased in January 1990, are made of alloy 6351-T6.

Cliff Impact DOT-3AL cylinders were made from alloy 6351-T6 before July 1990, at which time Cliff
Impact changed to alloy 6061-T6.

Catalina Cylinders did not produce any DOT-3AL cylinders from alloy 6351-T6; therefore, cylinders manufactured by Catalina are not subject to this notice.



So for Luxfer "before the dates indicated below likely are made from alloy 6351-T6" which means that there is possibility that cylinders made before the date could actually be made from 6061 but unsure. However, those made after the date are certainly not 6351.

For Water Kidde there is a possibility while small that a cylinder could be from Jan 1990 and would definitely be made from 6351

For Cliff Impact there is a six month period in 1990 where cylinders were made form 6351.

So the 1990 date is arbitrary and capricious. That said I could see for Luxfer a date of 1988 or earlier because of the different sizes. Further, no Walter Kidde, and for Cliff Impact no 1990 and before


Superlyte27 I may have asked you this before but does it not bother you that a person who can not perform a simple chart lookup is filling high pressure cylinders? Reading crown markings is not that hard. And the advisory is not that complicated.


That said I do understand the concern and have no problem with a shop declining Al6351 cylinders I just have problems with arbitrary and capricious dates.

 

[Superlyte27]

I find the above statement interesting. For a couple reasons:

Notice No. 94-7; Safety Advisory; High Pressure Aluminum Seamless and Aluminum Composite Hoop-Wrapped Cylinders

According to Luxfer USA data, the following types of cylinders stamped as manufactured by Luxfer USA
before the dates indicated below likely are made from alloy 6351-T6.All Walter Kidde DOT-3AL cylinders, of which production ceased in January 1990, are made of alloy 6351-T6.

Cliff Impact DOT-3AL cylinders were made from alloy 6351-T6 before July 1990, at which time Cliff
Impact changed to alloy 6061-T6.

Catalina Cylinders did not produce any DOT-3AL cylinders from alloy 6351-T6; therefore, cylinders manufactured by Catalina are not subject to this notice.



So for Luxfer "before the dates indicated below likely are made from alloy 6351-T6" which means that there is possibility that cylinders made before the date could actually be made from 6061 but unsure. However, those made after the date are certainly not 6351.

For Water Kidde there is a possibility while small that a cylinder could be from Jan 1990 and would definitely be made from 6351

For Cliff Impact there is a six month period in 1990 where cylinders were made form 6351.

So the 1990 date is arbitrary and capricious. That said I could see for Luxfer a date of 1988 or earlier because of the different sizes. Further, no Walter Kidde, and for Cliff Impact no 1990 and before


Superlyte27 I may have asked you this before but does it not bother you that a person who can not perform a simple chart lookup is filling high pressure cylinders? Reading crown markings is not that hard. And the advisory is not that complicated.


That said I do understand the concern and have no problem with a shop declining Al6351 cylinders I just have problems with arbitrary and capricious dates.

When you have a store that's been opened for 40+ years, with 100k+ in inventory, thousands per year spent on liability insurance, thousands spent on rent, electric, compressor, etc, etc, etc.... you can run it anyway you want.

For us, we've found that people will not look at a chart. It's easier/safer for us to just say, "look at this one number, if it's 1990 or older and aluminum, dont' fill it."

Piece of cake, the world keeps spinning. And we like that.

 

[chrpai]

And people wonder where the term fill monkey comes from.

Sadly it doesn't stop at tanks. All kinds of crazy opinions exist on all topics diving.

 

[Superlyte27]

No one cares about your stuff more than you do. The same can be said for your businesses or mine.

 

[Rich Keller]

When you have a store that's been opened for 40+ years, with 100k+ in inventory, thousands per year spent on liability insurance, thousands spent on rent, electric, compressor, etc, etc, etc.... you can run it anyway you want.

For us, we've found that people will not look at a chart. It's easier/safer for us to just say, "look at this one number, if it's 1990 or older and aluminum, dont' fill it."

Piece of cake, the world keeps spinning. And we like that.

The world will keep spinning and so will my tires as I leave your place and go to one of your competitors. Or I could go to one of these places to get a fill, the same places you take tanks to get hydroed. PHMSA - Cylinders - Authorized DOT Cylinder Retesters: Domestic

 

[Superlyte27]

Oh, no, please don't go, lol...

You can please some of the people all of the time, all of the people some of the time, but you can never please all of the people all of the time. We're okay with disagreeing on this tank issue. Frankly, we've been here since '72. We've got a great customer base. We've got no competitors except the internet, and we'll beat any price anyone comes to us with. We've watched 8 dive shops come and go in the last two years in our county. We're still here. We don't have to win every customer over, 99% of them is just fine by us.

And honestly, we're okay if you don't see things our way, you're still welcome to shop here and get your tanks filled elsewhere. It won't hurt our feelings at all.