Any way to tell what gas is in bottle?


I got a torch set from Craigslist for pretty cheap money. It came with
a cart and a bottle of gas. The guy is real sure it's O2, but the
label had CO2 and Argon, with the percentages faded totally away. And
the fitting is not the "normal" O2 fitting, but seems to match that of
CO2 bottles.
The gas itself has no smell at all. And I held a lit match in front
while I just let a little gas squirt out. I would have expected O2 to
have fired that match right up, but it just put it out.
I was hoping it was O2, as that would have saved me from buying a
bottle. But even without it, the cart, regulators, hose, torch, and
tools is worth what I paid.
So is there any way to tell what's in there? I'd like to sell it, but
I think "mystery gas" wouldn't get a lot of takers.
--Marc
Reply to
MarcG
Loading thread data ...
on Fri, 12 Sep 2008 07:23:20 -0700 (PDT), MarcG wrote this wisdom:
Well your right, a smouldering piece of wood should flare up in O2 but since it was put out it means a none combustible gas, probably CO2 or one of the inert gases like Argon.
Most probable that what is on the label is inside the bottle
Reply to
Simon. (Zed Are Seven)
Have a look at
formatting link
if that isn't the one poke around there - you'll figure it out.
You can swap your cylinder straight over for an oxygen one if that's what you're worried about.
Grant
Reply to
Grant Erwin
With the cylinder cap off, look on the side of the brass valve for the CGA number. If it says CGA 580, that is an inert gas cylinder, and thats why there's a lable that says Argon/CO2.
Grant Erw>
Reply to
Barry
Mine is 7/8", so it looks like it's either CGA-034 or -035. That would make it inert gas or industrial air, if it follows that description. But, you're right, I only really care if it's oxygen, and I didn't know I could just swap it. Solves my problem, thanks.
--Marc
Reply to
MarcG
. . .
So I guess my next question is - What size is the bottle? I measured it as 22" tall, not including the valve, and 6-1/2" across.
--Marc
Reply to
MarcG
On Fri, 12 Sep 2008 07:23:20 -0700 (PDT), MarcG
For a chart of compressed gas bottle sizes, see:
formatting link
your description, it seems that it could be either a =93C=94 or =93CL= =94 size gas bottle.
I=92d not heard of CGA 034 & 035 fittings before, but I found this site:
formatting link
034 Right hand threads, CGA 035 Left hand threads. The fittings are good for 200 psig max, so I=92m guessing that goes for the bottle as well. Hope you solve your mystery and protect yourself if you decide to use them.
Reply to
Denis G.
That's different - I've only ever seen bottle sizes in cu ft (excepting acetylene bottles). That is, cu ft of STP gas that the bottles holds compressed. E.g., my small-ish C25 bottle is a 40 cu-ft'er.
Yikes - 200 PSI!! That would be marginal for propane, never mind any seriously compressed gas. Propane safety vents release at 175 PSI, IIRC.
Bob
Reply to
Bob Engelhardt
=93CL=94
Hi Bob, If you have a "C" sized bottle, to get the cu.ft quantity you're looking for --> 2800 psi / 14.7 psi x 0.24 cu.ft =3D 45.7 cu.ft (Well .... close enough to your 40 cu.ft!). P1 x V1 =3D P2 x V2. Anyways, I think that's how it works. (Corrections welcome.)
I wonder if there's a DOT number stamped on the bottle that MarcG has. Maybe that will verify the rated tank pressure. Air Products lists similar sized tanks for "High" and "Low" pressures and they have different DOT #'s. See:
formatting link

Reply to
Denis G.
Yeah, I understand that it can be converted easily enough. I was just commenting on the naming convention used to identify the bottle. E.g., "C" vs "40 cu ft".
Bob
Reply to
Bob Engelhardt
I'll check on any stampings tonight, if I have a chance.
Reply to
MarcG
It's got DOT3AA2015 stamped on it. That fits the C tank, and I believe says it's good for 2015 PSI, based on this handy marking guide:
formatting link
from that, I think the tank may be out of date. I found a "SPUN", which I don't know what it means, and "6-88+", so it was tested 20 years ago with a 10-year retest and 10% overfill.
There are a couple other markings below the DOT and serial number, such as a rounded "M" and a "C".
My guess on the CGA style of valve was only a guess, based on the internal dimensions of the outlet. There is a "CGA" on the valve, but the number seems to have been obliterated by someone wrenching the valve off.
--Marc
Reply to
MarcG

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.