Oxy-Acetylene tanks

[john k]

I wanted to share with the group a pic of an oxygen tank.   An OLD oxygen tank.  Ever look on the sides of the green tanks/bottles, at the inspection dates?   Every few years, they get pressure tested, and the date is stamped right into the steel.  At the farmstead I blacksmith at, there is a green bottle back in the corner.   What you notice first is it has square steel foot, not round all the way to the floor.  The valve is recessed, 5/8 square or so.   The newest date on the bottle is 1948, then 41, 36, 31, 27, 21, 17, they keep going around the bottle.  At the top with the rest of the numbers is I am guessing the first date, 2-6-1906.  1906, which is about the time oxyacetylene welding came out of the factories, into the small shops.  I can only guess the shops, blacksmith shops that bottle has been in.  Anybody else see anything on the old side?

[mikeswrenches]

The oldest dates I have seen were on Oxygen bottles in the Buick foundry.  They started with 1928(when the foundry was built) and continued every 5 yrs.  If memory serves high pressure gas bottles have to be hydro-statically checked every 5 yrs. or they can't legally be filled.  Dive tanks are another one that must be checked every 5 yrs.  I'm sure there are many more that fall in this category.

Mike

[rusty]

In theory, as the gas is dry and won't corrode the tank, and the steel presumably is good, and the pressure stress is always within the elastic range of the steel, there is no limit to the potential age of a gas cylinder.

There is , nonetheless, something just a touch scary about standing next to 2000 pounds of explosive force being contained by a piece of metal going on 100 years old....

[john k]

I went back to my photos of this tank.  The newest stamp is 2-54, after that it was retired, or stuck somewhere it was never taken back for refill.  So in theory it could have been in use til 1958, making it a working tank for 52 years!   Just for comparison, when it was built, the Stanleys were still building steamers,  the Wright Brothers were just starting to be taken seriously, and Henry Ford  was dreaming about a Universal Car, he would later name the Model T. 

[Aunt Phil]

In theory, as the gas is dry and won't corrode the tank, and the steel presumably is good, and the pressure stress is always within the elastic range of the steel, there is no limit to the potential age of a gas cylinder.

There is , nonetheless, something just a touch scary about standing next to 2000 pounds of explosive force being contained by a piece of metal going on 100 years old....

You completely discount the ability of dullard government employees to write regulations. 

There was a procedure created in the 70s that allowed cylinders over a certain age to be derated and only filled to 1500psi.  Many suppliers loved that one because they generally sold the 3/4 fill to a home shop weldor or a buyer they didn't like.

The biggest hazard to old cylinders is worn threads on the neck that allow the bell to fail to properly seat.  The cylinder in the picture would require revalving to return to service under current regulations, but if the bottle passes hydro it'll be good to go.

Chances are the hydro operator will want it as an antique.

[OilyRascal]

You completely discount the ability of dullard government employees to write regulations. 

I believe the generally accepted interpretation of dullard is something along the lines of "not very bright".  Are you making a general statement suggesting the intelligence of all government employees?

The biggest hazard to old cylinders is worn threads on the neck that allow the bell to fail to properly seat.

With all due respect in my asking......Do you have anything factual to present that might back this claim?

[Aunt Phil]

You completely discount the ability of dullard government employees to write regulations. 

I believe the generally accepted interpretation of dullard is something along the lines of "not very bright".  Are you making a general statement suggesting the intelligence of all government employees?

No, all would be too broad.  In the course of over half a Century interfacing with government employees I've met at least 6 who knew their job and did it to the maximum permitted by their superiors in the chain of command. 

The biggest hazard to old cylinders is worn threads on the neck that allow the bell to fail to properly seat.

With all due respect in my asking......Do you have anything factual to present that might back this claim?

You could begin with the extensive OSHA (Oh Shit Happened Again) bulletins regarding lifting cylinders by the bell or employing lifting devices that attach to the bell threads on a cylinder.

Then you could factor in 50 years of seeing bells slapped with everything short of a crane ball to break them loose.

[OilyRascal]

No, all would be too broad.  In the course of over half a Century interfacing with government employees I've met at least 6 who knew their job and did it to the maximum permitted by their superiors in the chain of command. 

You could begin with the extensive OSHA (Oh Shit Happened Again) bulletins regarding lifting cylinders by the bell or employing lifting devices that attach to the bell threads on a cylinder.

Then you could factor in 50 years of seeing bells slapped with everything short of a crane ball to break them loose.

<shakes head>

All but six government employees are dullards, and I should leverage a government agency to substantiate your hazard claims. 

I should hope the six you met worked at OSHA  :-)

[Papaw]

Keep it friendly, fellas.

[OilyRascal]

There are published studies, lessons learned, and failure analysis on compressed gas cylinder failures available - free, online.  I've not read anything that would have me conclude there is a primary cause of failure with older cylinders.  Its seems it may have as much to do with the contents as the cylinder itself.

Examples:

Studying the failure of an HF cylinder at UC Santa Barbara and a HCN cylinder failure at a US Army lab at Edgewood, Maryland:

http://ucih.ucdavis.edu/docs/i_cylinders.pdf

Another on an HCI gas cylinder valve

http://www.sciencedirect.com/science/article/pii/S1350630799000369

Keep it friendly, fellas.

Yes sir - I am.  As previously stated, no disrespect intended.  With all the friendliness and respect possible to anybody involved or reading - it is not right to call out a group of people in a negative way due to their membership - whatever their membership may be.  It is not right, but I'll move on.

[anglesmith]

When I was in Newguinea in the 1970s a wartime Japanese oxygen cylinder exploded after 25 years of being rung several times a day with a iron bar to call in plantation workers to meals. The unfortunate ringer of that day was killed!
I also saw them used in Rabaul (New Britian), half buried upside down as roadside bollards, I often wondered how many of those were still full! Every thing has has a failure point when dealing pressures like that especially when abused or neglected.
Graeme


clarification

[aametalmaster]

In theory, as the gas is dry and won't corrode the tank, and the steel presumably is good, and the pressure stress is always within the elastic range of the steel, there is no limit to the potential age of a gas cylinder.

There is , nonetheless, something just a touch scary about standing next to 2000 pounds of explosive force being contained by a piece of metal going on 100 years old....

You completely discount the ability of dullard government employees to write regulations. 

There was a procedure created in the 70s that allowed cylinders over a certain age to be derated and only filled to 1500psi.  Many suppliers loved that one because they generally sold the 3/4 fill to a home shop weldor or a buyer they didn't like.

Cylinders can only be used for 99 years then they are scrap. I see lots of 1913 and 1917 ones at work. Seems like Airgas bought them all up. The high pressure (oxy, N2, Argon) and others are converted to lower pressure as the age goes on like for CO2 use. Those are the oldest ones as i said above 1913 and newer. They were at one time Oxygen...Bob