Steel 72’s passed hydro, but .

[KGNickl]

If they pass visual you are good to go. I have (4) steel 72 cu ft. PST tanks from 1978 and love them! Overfill them to 2400-2500 and they are comparable to a AL80, but with better buoyancy characteristics. Mine are not + certified on the current hydro, but I have yet to find a shop that won't fill them to 2400-2500 psi.

 

[oxyhacker]

Some people are just weird about anything old. They figure that just because they are getting weaker and more brittle as they age, everything else must be too. Actually, some metals age harden and can become brittle from time alone, but steel isn't one of them. It's cycles, not age that matter, and even cycles only matter a little. Dive shop people might not understand this, but a hydro tester ought to.

You might try to cheer them up by pointing out that your tanks are newer than the USA's main line bomber, the B-52, which is still in full time service!

 

[DA Aquamaster]

It is a bit off topic, but when the last B-2 gets flown to the bone yard, the crew will probably be picked up and flown home in a B-52. (The B-52 is already well on its way to outliving the B-1 that "replaced" it in the late 1970's.)

 

[Flightlead]

People get nervous about the age, but it is a fear based on ignorance. The oldest welding tank I have seen come through for hydro test was made in 1911 and it still passed with flying colors

1911? Really? wow, cool. As a bit of a history buff that geeks me out! Almost 100 years old. Manufactured only 8 years after the Wright brothers first powered flight, 3 years before WWI, 8 years before the Volstead act. Wow, think about the different welders that used that tank and what they might have experienced. How cool!

 

[superstar]

Last year I got a oxygen welding cylinder with a 1907 hydro date. The guy from the welding supply company told me that type of cylinder was first made in 1905. This really builds my confidence in the staying power of the low pressure steel cylinders. That cylinder has out lived most industries in my home town. Steel is real.

 

[Gilldiver]

It is a bit off topic, but when the last B-2 gets flown to the bone yard, the crew will probably be picked up and flown home in a B-52. (The B-52 is already well on its way to outliving the B-1 that "replaced" it in the late 1970's.)

The current B-52 models were built in the early 1960's and are not due to be taken out till 2042 or 2046. The first B-52's flew in 1949 or 1950. Not bad for a 90 year airframe family. Other aircraft that are getting long in the tooth are the UH-1's which first flew in 1958, Sikorsky S-61's and S-58's from 1961 and 1958 all are still flying daily. Then there are any number of DC-3's (C-47 or R4D) from the 30's and 40's around.

Age in aircraft and tanks doesn't matter - it is condition and maintainance that does.

 

[captain]

1911? Really? wow, cool. As a bit of a history buff that geeks me out! Almost 100 years old. Manufactured only 8 years after the Wright brothers first powered flight, 3 years before WWI, 8 years before the Volstead act. Wow, think about the different welders that used that tank and what they might have experienced. How cool!

For while I worked for Linde Gas products (now Praxair). I would always check the original hydro dates on tank that came through our facility. It was not unusual to find oxygen cylinders made in the late 1890's still going strong.

 

[Gilldiver]

Here is another thing to look for on a welding or storage tank.

On the neck near the serial numbers or Hydro numbers look for something that appears to be a windowpane. It will look like 4 blocks together or a square with a "t" inside that touches all 4 sides.

If you look real close you will find that there are 4 straight lines that fill in the Nazi Swastika. All of the Linde bottles made in Germany between 1935 and 1945 were marked with the Swastika. In the US this emblem was "filled in" during the war. If you look around you will find it.

 

[captain]

Here is another thing to look for on a welding or storage tank.

On the neck near the serial numbers or Hydro numbers look for something that appears to be a windowpane. It will look like 4 blocks together or a square with a "t" inside that touches all 4 sides.

If you look real close you will find that there are 4 straight lines that fill in the Nazi Swastika. All of the Linde bottles made in Germany between 1935 and 1945 were marked with the Swastika. In the US this emblem was "filled in" during the war. If you look around you will find it.

That is most likely an made up story. I have an oxygen cylinder in my shop right now that was made in 1980 with that symbol. It is the symbol for the facility that did the original hydro. Before DOT standardized the identifier with the 4 digit identifier between the month and year facilities had their own symbol. Sometimes it was before the month and date, sometimes between and sometimes after the month and date. Back in the 60's the local dive shop was Roland's Surplus and Sporting Goods. They stamped ROL behind the month and date.

 

[Peter_C]

If anyone wants some steel 72's that are not in hydro or vis I will let them go for cheap like $40 each. I have a smaller set of steel 63 doubles available too. PM me if interested.
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