acetelene tanks

And if the valve stem is just a little square shank with no knob, it's almost certainly an acetylene tank.

not always, if the tank is a "B" cylinder, most acetylene regulators wont fit without an adaptor like this:

It has a knob on the valve. It is bigger than a "B" tank and was painted silver. I strongly suspect it is a CO2 tank.

Acetelene tanks have some sort of "matrix" in them and contain acetone - this should make the tank heavier and might dampen the "ring" of the empty tank?

Left sit in the sun it developed a bit of pressure, and when I cracked the valve there was no odour - so it pretty well rules out acetelene, I would think.

I can't decipher the whole thing but it looks as if the last hydro test was done October 1972, also done two times before that (April 1967 and April

Shawn

An acetylene bottle that size often has welded seams and is relatively light. A CO2 bottle will be seamless and heavy.

You're right. They're filled with a porous concrete and this is saturated with acetone, and the acetylene is dissolved into the acetone. Makes things safe at the pressures we have to store the stuff at. Free acetylene is dangerous above 15 psi. You sure wouldn't want to fill anything else with acetylene.

Dan

Jim

Careful how you edit your posts. I did not write that.

sorry Jim

walt

What color is the tank?

If black, it's likely an acetylene tank, if silver a CO2 or other inert gas tank, and if green it's an oxygen tank.

Then too, all of my acetylene tanks have a flat top and bottom due to the presence of an external shroud on the tank intended to shield the valve from physical damage.

Harry C.

"do not sniff unknown gas bottles, that's bad policy"

Jim, sniffing an unknown gas is a standard technique in analytical chemistry, although there is a specific safety procedure employed in doing so. That is, one wave a cupped hand through the excaping gas, then bring that hand within range your nose and never deeply inhale (our sense of smell is very acute with only a highly diluted whiff). Acetylene, sulfur dioxide, hydrogen sulfide, ammonia, chlorine, cyanide (hydrogen cyanide) and other gasses with distinctive odors are readily identified using this method. Unfortunately, many fuel gases have no distinctive odor (hydrogen, butane, methane, propane, etc.).

In addition to analytical chemists, ordinary people working with either toxic or explosive gas are taught this technique as part of their training in the fundamentals, so that they can identify the smell of toxic and some explosive gasses when entering an enclosed structure. For example, most of us here already are familiar with the odor of acetylene, but how many without sniff training would associate the rather pleasant odor of cyanide (it smells exactly like roasting almonds) with a possibly lethal building atmosphere? Realize that most of our population does not recognize the odor of roasting almonds, simply because many have never roasted almonds. :-)

Harry C.

No it's not. It may have been at one time, but this is no longer true. Nobody teaches this any more, and anyone who does this is foolish and will at some point pay the price for it.

One friend of mine did this with hydrogen sulfide. Fortunately the bottle rolled way from him when he fell to the floor and he survived.

Another co-worker said "what smells like garlic?" when he got a whiff of Arsine. Fortunately he only received some minor kidney damage from that incident. The usual rule for that is, if you detect an odor at all, you are in *serious* trouble.

Anyone who picks up an unknown, used gas cylinder and deliberately whiffs the contents is playing a very, very dangerous game.

Same with pipetting viruses by mouth.

Jim

Knowing a bit of the history of this tank, I KNEW it was welding related or beverage related This narrows it down to either oxygen, fuel, or sheilding gas for welding, or CO2 for beverage carbonation.. Knew it wasn't Oxygen - as O2 bottles have LH threads. No smell means not Acetelene, and not propane or MAPP. That leaves shielding gas or CO2, Argon, Helium, or a mix. My voice didn't get squeaky, so it's likely not helium, and none of the others are dangerous in small quantities.

I'm pretty sure it was CO2 - and being as far out of date as the hydro-test appears to be on it, it will likely end up in the scrap bin.

That's great if you really knew for certainty where it came from and who was using it, and what it was being used for.

The question at hand is, are you certain enough to bet your life on it?

Jim

Don't be too sure - As long as it isn't rusty, or wasn't dropped too many times, it's worth a try. Or just turn it in as a straight exchange and let them worry about the hydro. I bought an original military 2.5# CO2 extinguisher that was last tested... Let me go grab it.

Army-Navy CO2 Fire Extinguisher Model E-2 1/2-B B-2, C-2 Serial #F-491155 Randolph Industries, Chicago 11 Illinois JAN E 468 ICC 3AA1800

The guys at Pioneer Fire were going "Military, Spun tank, that'll fail." "It's passed before, give it a try." Passed with flying colors (hence the 4P85 recert and refill) - popped off the belly band, painted it red, put the belly band back on, and put it on my matching vintage generator.

I've seen a LOT of "antique" bottles in daily use - go look at the first entry on the long list of recert dates on some of the ones out in the bins, and you'll get a surprise.

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Do oxygen bottles have LH threads there? Here ( Australia) they have a RH thread but acetylene and LPG/propane?butane gas bottles have the LH thread. The nut part of a union for these gases has a groove turned in the outside of it to show that it is a LH thread.

Tom