Co2 Bottle Safety Lesson
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doglet
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My brother has just told me that the cylinder was filled with 1.6kg of gas so this looks more like an overfilling issue. I have a feeling that the person filling has somehow confused the "Empty = 2053g" label I have put on the cylinder and have tried to fill with 2kg. I put this label on so I could check on my usage.
Having found out that bit of info I still think there is a bit of an issue with the labelling on the cylinder. If it is stamped with TW=1.5kg, then can we assume that 1.5kg of carbon dioxide should be able to be put in? Overfilling would of course be a danger but an engineering factor of safety would be built in so that the burst valve would break if overfilled to say 2kg or if the bottle temperature rose suddenly. Anecdotal evidence with these cylinders says that it should be less than 1.5kg with one respected board member here who is a refiller, MHB, stating that he would only put 1kg in. I have been googling and have found that CO2 cylinders should only be filled to about 2/3 of their equivalent water volume (or something like that) - maybe the 2/3 or 1.5kg is the 1kg that MHB has stated?
Still finding out more info....
Here are some CO2 cylinder links for info:
CO2 cylinder venting - aquarium related
Catalina cylinders refill instructions - Mykegonlegs brand
Catalina cylinder storing instructions
UK safety authority (HSE) refill station compliance report
Having found out that bit of info I still think there is a bit of an issue with the labelling on the cylinder. If it is stamped with TW=1.5kg, then can we assume that 1.5kg of carbon dioxide should be able to be put in? Overfilling would of course be a danger but an engineering factor of safety would be built in so that the burst valve would break if overfilled to say 2kg or if the bottle temperature rose suddenly. Anecdotal evidence with these cylinders says that it should be less than 1.5kg with one respected board member here who is a refiller, MHB, stating that he would only put 1kg in. I have been googling and have found that CO2 cylinders should only be filled to about 2/3 of their equivalent water volume (or something like that) - maybe the 2/3 or 1.5kg is the 1kg that MHB has stated?
Still finding out more info....
Here are some CO2 cylinder links for info:
CO2 cylinder venting - aquarium related
Catalina cylinders refill instructions - Mykegonlegs brand
Catalina cylinder storing instructions
UK safety authority (HSE) refill station compliance report
This is why we fill very carefully and only to the weight limit on the bottle. I have said I dont believe the bottle in question can safely take 2.5Kg and only fill mine to 1Kg. there are about a dozen of these among my customers, no trouble with any of them so far (Touch Wood).
People keep dragging in 20 year old out of date bottles and expect me to fill them up, No Way.
I have staff and a duty of care Safety Must Come First
If you think $300 is too much to pay for a brand new bottle, with 10 years before it needs testing, at $30 a year its cheep life insurance.
MHB
(P.S.) this is not an ad all my locals know we sell bottles and they cant be shipped full so ask your LHBS.
People keep dragging in 20 year old out of date bottles and expect me to fill them up, No Way.
I have staff and a duty of care Safety Must Come First
If you think $300 is too much to pay for a brand new bottle, with 10 years before it needs testing, at $30 a year its cheep life insurance.
MHB
(P.S.) this is not an ad all my locals know we sell bottles and they cant be shipped full so ask your LHBS.
doglet
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Thanks MHB for your quick response. The bottle I have has an 06 test date so it has the 10 year life insurance option on it 
. I agree that out of date cylinders are a no no I'd expect a kick up the bum from this forum if I was complaining about it!
I will look into several options including getting a brand new cylinder, Mykegonlegs or Air-up, or going down the rental path. I'll do some phoning around to see what I think is the best option. I will also talk to the original supplier to see if the burst disc is correctly rated as the bottle is a handy size if I ever want to take a keg anywhere.
. I agree that out of date cylinders are a no no I'd expect a kick up the bum from this forum if I was complaining about it!I will look into several options including getting a brand new cylinder, Mykegonlegs or Air-up, or going down the rental path. I'll do some phoning around to see what I think is the best option. I will also talk to the original supplier to see if the burst disc is correctly rated as the bottle is a handy size if I ever want to take a keg anywhere.
Doglet,
Whew, what a story. Glad to hear your bro came out OK.
My thoughts:
To me, TW = Tare Weight = weight of empty cylinder, not NW = Net Weight, or amount of gas.
Looks like someone made a simple mistake.
BB
doglet
Just to clarify
10 years from date of manufacture
5 years on subsequent tests.
The average life expectancy of an Aluminium CO2 cylinder is 20-25 years
Your test stamp is a retest, so should be good 2006 2011.
I am reasonably confident that the bottle was over filled and that if you replace the burst disc and limit future fills to 1Kg you will get good service from the bottle.
I got mine for the reason you gave, they are very handy, I send them out with a magic box on hire. The pisshead engineering students from Newcastle University got 5 and a bit 50 Litre kegs out of one.
If you decide not to use yours again, I would be interested, if you can get a burst disc. Yes I am that confident the bottle is fine and they are very handy.
MHB
Just to clarify
10 years from date of manufacture
5 years on subsequent tests.
The average life expectancy of an Aluminium CO2 cylinder is 20-25 years
Your test stamp is a retest, so should be good 2006 2011.
I am reasonably confident that the bottle was over filled and that if you replace the burst disc and limit future fills to 1Kg you will get good service from the bottle.
I got mine for the reason you gave, they are very handy, I send them out with a magic box on hire. The pisshead engineering students from Newcastle University got 5 and a bit 50 Litre kegs out of one.
If you decide not to use yours again, I would be interested, if you can get a burst disc. Yes I am that confident the bottle is fine and they are very handy.
MHB
doglet
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Ok - more research has been done.
These cylinders are to be filled with a maximum of 2.5 pounds (1.13kg) of CO2. There is what appears to be an original stamp of "2.5#CO2" on the cylinder.
Another way to arrive to this conclusion is from the dimensions of the cylinder with the water capacity being approximately 1.7L. My readings on the internet indicate that CO2 cylinders should only be filled to approximately 2/3 their water capacity, therefore approximately 1.13kg.
The original stamped markings T2.1KG TW4.6 indicates the empty cylinder weight is 2.1kg which is 4.6 pounds. I am unsure why there is an additional TW1.5KG stamp on the cylinder and this will be followed up.
The service pressure of the cylinder is 1800psi, this is stamped, and is the reasion why a 3000psi burst disc is supposed to be fitted.
Conclusions from this incident are:
1. In this incident the cylinder was overfilled and the burst disc failed like it is designed
2. Overfilling may have been caused by confusing stamping and unfamiliarity by the refiller with this size of cylinder. I suspect they usually get standard sized cylinders or extinguishers and fill them according to a chart.
3. Never store a CO2 cylinder in the cabin of you vehicle. If you have to due to driving a station wagon, hatch, van etc then have a couple of windows down.
4. Tell your refiller to only put 1kg of CO2 into these cylinders.
I hope this info is useful. I will probably continue to use this type of cylinder as the size is convenient if moving the odd keg around but I will also buy a bigger cylinder as I now have 6 kegs and 1kg just doesn't last long enough.
Take care with CO2 everyone.
These cylinders are to be filled with a maximum of 2.5 pounds (1.13kg) of CO2. There is what appears to be an original stamp of "2.5#CO2" on the cylinder.
Another way to arrive to this conclusion is from the dimensions of the cylinder with the water capacity being approximately 1.7L. My readings on the internet indicate that CO2 cylinders should only be filled to approximately 2/3 their water capacity, therefore approximately 1.13kg.
The original stamped markings T2.1KG TW4.6 indicates the empty cylinder weight is 2.1kg which is 4.6 pounds. I am unsure why there is an additional TW1.5KG stamp on the cylinder and this will be followed up.
The service pressure of the cylinder is 1800psi, this is stamped, and is the reasion why a 3000psi burst disc is supposed to be fitted.
Conclusions from this incident are:
1. In this incident the cylinder was overfilled and the burst disc failed like it is designed
2. Overfilling may have been caused by confusing stamping and unfamiliarity by the refiller with this size of cylinder. I suspect they usually get standard sized cylinders or extinguishers and fill them according to a chart.
3. Never store a CO2 cylinder in the cabin of you vehicle. If you have to due to driving a station wagon, hatch, van etc then have a couple of windows down.
4. Tell your refiller to only put 1kg of CO2 into these cylinders.
I hope this info is useful. I will probably continue to use this type of cylinder as the size is convenient if moving the odd keg around but I will also buy a bigger cylinder as I now have 6 kegs and 1kg just doesn't last long enough.
Take care with CO2 everyone.
