Refilling Adapter Kit for SodaStream Quick Connect W21.8 to CO2 Tank How it works: 1. Chill the SodaStream cylinder in the freezer for 1 hour before refilling. 2. Attach the CGA320/W21.8 fitting to a standard commercial CO2 cylinder. 3. Disconnect the quick-connect fitting from the black adapter. Tighten the black adapter onto the CO2 cylinder. Ensure the adjustment knob on top of the black adapter is fully turned upward (in the highest position). Do not turn the knob downward — this would depress the 6 mm valve pin and close the valve, preventing CO2 flow. 4. Reconnect the quick-connect fitting. 5. For larger CO2 cylinders: position the cylinder upright, or lay it horizontally — depending on whether it contains a dip tube (siphon tube). 6. Slowly open the main valve on the CO2 cylinder. Opening too quickly may trigger the safety shut-off mechanism. Listen for steady gas flow to confirm proper operation. 7. Refill for approximately 15–20 seconds. The cylinder is then fully charged. 8. Close the main valve on the CO2 cylinder. 9. Open the bleed screw to release any residual pressure. 10. Unscrew and remove the adapter. Important Notes: 1. If liquid CO2 is present, invert the CO2 cylinder during refilling — especially if your cylinder lacks a dip tube. 2. Ensure the SodaStream cylinder is empty and pre-chilled for optimal fill capacity. 3. Always open the CO2 cylinder valve gradually to avoid triggering the safety valve (6 mm pin) on the SodaStream cylinder. 4. This adapter is not compatible with RPV (Residual Pressure Valve) systems. Check your CO2 cylinder before ordering. If your cylinder has an RPV, select the “RPV Pushing Adapter” option. Some RPV valves can be removed using a hex wrench — verify compatibility prior to purchase.