Refill Your CO2-tank

Soda Stream Alcojet Soda-Club REFILL Gas cartridge dioxide cartridge CO2, DIY.

This adapter allows you to link Soda-Club / Soda Stream on a standard w21.8-14 OR CGA-320 Valve Donor CO2 Tank and refill.

It is not difficult and takes only minutes. You must buy donor tank and Sodastream tank.

So, anyway, this is the way I do it. First I put the empty CO2 bottle in the freezer for a few hours so it becomes about minus 15 – 20 degrees Celsius cold. This is because a cold bottle accepts more CO2, filling takes place at bottle pressure and not with a pump. By cooling the receiving bottle the pressure in it is reduced.

I have screwed on the adapter to my 6kg pub bottle that costs €25 to fill with food quality CO2 (have bargained, easy to do when you are helping the environment).

CO2 bottles for drinks have a tube internally that reaches the bottom. (CO2 extinguishers do not have a tube) so what comes out is liquid CO2, so I do not have to upturn the bottle. The adapter can only fit one way, with different threads for the big and little bottle.

I fit the little adapter by hand. Then I open fully quickly and wait for it to stop blowing, about one minute. Close the valve, unscrew the little bottle and weigh it. Empty weight is marked on the bottle 790 grammes, with 425 grammes of CO2. The bottle when full weighs 1215 grammes.

I get about 100 grammes with one filling so I return the bottle to the freezer.

When frozen I repeat the filling. I do that four times and arrive just under 1200 grammes full weight. That is enough; I have filled just about 400 grammes.

Have filled a fifth time but the bottle is overfull so I release some CO2.

This method suits me fine. When I am at the freezer and a recharge is needed I do it.

A one minute job done four times is much easier than driving off to buy expensive CO2.

425 grammes CO2 cost EURO 9 in the shop, that is EURO 21/kg. My large bottle costs EURO 25 to fill, EURO 1.8 to fill the 425 gram fizzy drink bottle. This cost I recover just by not having to drive to the shop so that after 6 fillings the adapter is paid for.

If anyone wonders, the adaptor does not fit the old 300 gramme Sodastream steel bottles. These have another screw thread. Today CO2 bottles must have a certain screw thread, different for different gases to prevent accidents. It must not be at all possible to attach the wrong gas in industry and medicine.

Small screw can jursteres so it pushes Alco2jet pin. It is not always necessary to press. Thread suit general CO2 6, 8, 10 kg tanks.


CO2 adapter is made of aluminum and brass. The two materials can be separated.

You must have a gasket. Plastic, cardboard or rubber. Donor tank you buy yourself. You can buy a used, often used for welding work or the like.


Different types of valve

If you have a valve that is flat, and you have problems with refill. Here is an instruction video on how to modify the dobbelt valve on sodastream/sodaclub co2 tank.



Alco2jet tank must be cold. Place in freezer 2 hours before filling.




Insted of using a gasket you can wrap it and seated tight like this.

If you look down at the apter, you will see a small screw at the center. That screw can be adjusted, and presses the center pin on the 425g CO2 tank when the adapter is fully screwed on.

Thereby you open the internal valve on the  425g CO2 tank and allowing the liquid CO2 to free-flow into your tank.

After your tank is filled, you need to keep the fill equipment ATTACHED but the donor tank turned off. Then you can unscrew the apter from the filled tank. As you unscrews the adapter from the filled tank, the center pin stops pressing in the valve, and the CO2 stays in the tank as it is supposed to.


Donor Tank is 50 bar when it is liquid and it is full. Alco2Jet is pressure tested to 250 bar.


Remember safety glasses, work gloves and common sense.

See how it works:



Please do not fill the tank 100% with liquid CO2. There must be a gas pocket. The liquid CO2 expand a little with temperature.

The tank is says 250BAR, and liquid CO2 is never more than 50BAR.

Most tanks has a Security Nozzle that blows if the pressure gets to high, it blows at about 100 BAR.

If you look at the gold end of the CO2Dapter-II™ you will see a silver center pin. That pin presses the center pin on the FreedomValve™ when the adapter is fully screwed on and seated tight, thereby opening the internal valve on the FreedomValve™ and allowing the liquid CO2 to free-flow into your carbonator tank. In summary, when the CO2Dapter-II™ is fully screwed on tight onto an empty carbonator tank, the tank has a clear, open, and unobstructed opening to the outside world. What he is doing is filling the tank, but he is also letting it all leak out again when he removes his filling equipment BEFORE he unscrews the CO2Dapter-II™ from the now FULL tank. He’s letting all the CO2 back out! That explains the frosty tank, he just wasted the entire fill. 

After your tank is filled, he needs to keep his fill equipment ATTACHED but the main supply tank TURNED OFF, then he can unscrew the CO2Dapter-II™ from the filled tank. As he unscrews the adapter from the filled tank, the center pin stops pressing in the valve, and the CO2 stays in the tank as it is supposed to.

If he follows this procedure it will work. If he does not, gas will just leak out. Looks like we need to add this to our instructions, we just expect the paintball people to know more than they really do, then again he’s probably not done too many refills of Sodastream tanks.





6 Responses to “Refill Your CO2-tank”

  • Artem:

    Hi! I live in Russia, can I get this wonderful device ?


    I have two CO2 cylinders the same as the one you showed on the video. Is there a name or a model number for the adapter (any specification), what is the price and where to order it.




    Hi, I know where to order the adapter now. Do you ship to Hong Kong.
    I have two CO2 cylinders which are the same that you used in the video.
    My CO2 supplier, The Hong Kong Oxygen, is going to give me a 22.7.KG cylinder (Code-241-HR)with Gauge Pressure:5100kPa (740psig)at 15 degree C and Outlet Connection is BS341 No.8.
    Could the adapter be used with the said CO2 cylinder.


    • admin:

      You pay en Euro, so that depends on how PayPal convert U.S. Dollars to Euro.

      The adapter is 53 euro, that is about $75
      and shipping is 20 Euro, that is $28

  • chul-kwon:

    i’m using a CGA-326(22mm) co2 tank.
    and.. cartridge is flat valve..
    is adapt it?

    Thank you

    • admin:

      I only have the CGA-320 Valve, but it is easy to replace. You just put a new one on that fits your donor tank.

      If your valve look like the one in this top picture, then it is not good.

      But you can buy a good one, and hold on to it. Electrolux has a refrigerator that comes with a good valvet, maby you can ask at a store that sell refrigerator.


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