I have a 5# tank I keep in my kegerator and I just won a 20# tank on ebay. Rather than make a hole to run lines to have the 20# on the system outside of the fridge, I was thinking I could keep the 5# tank in there and fill it off the 20# as needed. What equipment does one need for this and how is it done? I remember in college there was a place that filled small tanks off their 50# (I think) tank and it seemed to just be a hose between the two and they opened both valves for a few min. Is it that easy?
How to fill one CO2 tank from another?
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Suthrncomfrt1884
Well-Known Member
I can't see it being that easy. I think you should consult your local gas supplier and see what they say.
The easiest way is to have a large siphon tank. For you, that would be your 20# tank. It is most likely not a siphon tank, but you can get your gas supplier to do that for you. If you don't want to put a siphon tube in the tank, you will have to turn it upside down.
The reason for this, is you need to fill the liquid into the other tank, not just the gas, otherwise you will only have a small fraction of the gas that you need in the smaller tank.
You will also need a high pressure transfer hose, the same type used in paintball gas fill stations.
You will also want a very accurate scale, as you don't want to overfill the tank and rupture the safety disc.
You should also know that there is a safety concern here as well if you are not careful.
Overall, I would say it is easier to use the 20# tank outside of your kegerator as your primary tank, and when it goes empty, use the 5# tank as a backup/spare.
The reason for this, is you need to fill the liquid into the other tank, not just the gas, otherwise you will only have a small fraction of the gas that you need in the smaller tank.
You will also need a high pressure transfer hose, the same type used in paintball gas fill stations.
You will also want a very accurate scale, as you don't want to overfill the tank and rupture the safety disc.
You should also know that there is a safety concern here as well if you are not careful.
Overall, I would say it is easier to use the 20# tank outside of your kegerator as your primary tank, and when it goes empty, use the 5# tank as a backup/spare.
Mongo64
Well-Known Member
The problem with doing this is that you could overfill the tank. Compressed CO2 is in a liquid state at room temp but becomes gas at around 100deg F and the pressure will increase greatly. Even a properly filled tank can exceed the design pressure if it is exposed to 120deg F temperatures (the safety valve is going to vent hopefully). Overfilling will get you to this point that much quicker.
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Go to your gas supplier. They'll sell you and do everything you need. This isn't something to mess with if you're clueless. However, I asked the same question and was told by my supplier that I'd want a minimum 50lb tank if doing this because with a 20# I'd really get 1, maybe 2 fills out of it.
I'm not an expert, and I didn't stay at a holiday inn last night. But you can refill your own tanks. (Insert standard "use at your own risk" disclaimer here. (x))
you need one of these:
http://pictures1.kyozou.com/pictures/_11/10544/10543612.jpg
and the correct fittings to change it to CG-320 threads. (basically a regulator stem and coupling)
Change your large tank out for a siphon tube one. Most places will actually swap one for the other without much trouble.
Put on safety goggles then:
Hook up the refill kit to both tanks. Keep all valves closed (small tank, large tank, refill and vent valves.)
Put the small tank on your scale (attached to the refill hose.) Tare it out.
Open both tank valves.
open the fill valve for half a second. Close it.
open the vent valve. This chills the small tank and you can get more CO2 into it this way.
Close the vent valve and open the fill valve. Fill your small tank to the recommended weight. Don't overfill!
Enjoy.
you need one of these:
http://pictures1.kyozou.com/pictures/_11/10544/10543612.jpg
and the correct fittings to change it to CG-320 threads. (basically a regulator stem and coupling)
Change your large tank out for a siphon tube one. Most places will actually swap one for the other without much trouble.
Put on safety goggles then:
Hook up the refill kit to both tanks. Keep all valves closed (small tank, large tank, refill and vent valves.)
Put the small tank on your scale (attached to the refill hose.) Tare it out.
Open both tank valves.
open the fill valve for half a second. Close it.
open the vent valve. This chills the small tank and you can get more CO2 into it this way.
Close the vent valve and open the fill valve. Fill your small tank to the recommended weight. Don't overfill!
Enjoy.
TBrosBrewing
Well-Known Member
If this is what you want to do, you will need:
Paintball tank fill station $50 from most online paintball stores
Accurate kitchen or hanging fish scale $20
Extra CO2 tanks $15
Larger CO2 with or without a dip tube.
If without a dip tube, you can invert your large tank and hold it in place with a wood vice attached to a heavy bench. This is what I do, I have 3 20oz tanks that I rotate though and they are much more portable than the 20lbs tank that I have.
As for how to do it, look up how to fill a paintball tank online. Your fill station should also come with instructions.
A word of caution, pay very close attention to what you are doing. If you overfill you can easily rupture your burst disk, there is little chance of you hurting yourself, but you will loose a significant amount of CO2.
It isn't difficult and its great for carrying kegs to parties.
Paintball tank fill station $50 from most online paintball stores
Accurate kitchen or hanging fish scale $20
Extra CO2 tanks $15
Larger CO2 with or without a dip tube.
If without a dip tube, you can invert your large tank and hold it in place with a wood vice attached to a heavy bench. This is what I do, I have 3 20oz tanks that I rotate though and they are much more portable than the 20lbs tank that I have.
As for how to do it, look up how to fill a paintball tank online. Your fill station should also come with instructions.
A word of caution, pay very close attention to what you are doing. If you overfill you can easily rupture your burst disk, there is little chance of you hurting yourself, but you will loose a significant amount of CO2.
It isn't difficult and its great for carrying kegs to parties.
