TR21×4 CO₂ Soda Maker Cylinder Adapter Installation Guide
Applicable Products:
Cylinder Adapter Tr21x4 to W21.8 / CGA320 Male Thread
Cylinder Adapter Tr21x4 to W21.8 / CGA320 Male Thread
TR21x4 Female to 5/8-18 UNF Male CO₂ Adapter for Gas Cylinders
TR21x4 Female to 5/8-18 UNF Male CO₂ Adapter for Gas Cylinders
1. Initial Installation
After receiving the product, you can first install and use it with the pre-adjusted stem length.
First, screw the adapter onto your device, then connect the assembly to the TR21×4 threaded CO₂ cylinder and tighten it until a proper seal is achieved.
2. Adjust the Stem Length if Required
Different brands of CO₂ soda cylinders and compatible Soda Maker CO₂ bottles may have variations in valve core height and sealing structure. The TR21×4 CO₂ adapter features an adjustable stem design to fit different cylinder valve specifications. If stem length adjustment is required, please follow the steps below:
① Use a flat-head screwdriver to adjust the stem length. First, turn the stem counterclockwise to retract it until the stem is slightly below the sealing ring surface.
② Screw the adapter onto the cylinder until you feel slight compression from the sealing ring. Do not overtighten.
Note: Do not use a wrench, as excessive tightening may over-compress the sealing ring and affect sealing performance.
③ Keep the adapter installed on the cylinder and slowly turn the stem clockwise with a flat-head screwdriver. Stop adjusting when you feel slight resistance, or when you feel the cylinder valve core is about to be opened.
④ Remove the adapter, install it onto your device, and then reconnect the assembly to the cylinder. Tighten until properly sealed.
Check for CO₂ Leaks
After installation or during regular use, periodically check the seal between the CO₂ adapter and the soda cylinder to ensure a secure and leak-free connection. Early detection of leaks helps prevent unnecessary CO₂ loss and supports safe operation.
- Apply a small amount of soapy water around the connection area, especially near the sealing point.
- Observe whether continuous bubbles appear or listen for any hissing sound that may indicate gas leakage.
- If leakage is detected, release the remaining gas pressure safely before removing the adapter.
- If the adapter needs to be reinstalled, repeat the complete installation procedure and replace the sealing ring with a new one before reconnecting.
Important Notes
- Adjust the stem only enough to open the cylinder valve core properly. A longer stem is not always better. Excessive adjustment may open the valve core too early during installation, causing CO₂ leakage.
- If the sealing ring feels dry or installation resistance is high, apply a small amount of silicone grease to the sealing ring surface. This helps installation and extends sealing ring service life.
- Once installed and there is no gas leakage, avoid frequent removal to reduce wear on the sealing ring.
- If removal is required while the cylinder still contains gas pressure, slowly unscrew the adapter while pressing the release button/valve on your device to release the residual gas trapped between the cylinder and the adapter before fully removing it. If the adapter is difficult to remove, a suitable wrench or tool may be used to assist with removal. Do not apply excessive force to avoid damaging the threads or sealing components.
- Do not quickly remove the adapter while under pressure, as sudden gas release may cause inconvenience or damage to sealing components.