CO2 Locator
Tool
Valve / Regulator Fit Checker
This tells you what fits what (standard CO2 vs SodaStream), what adapter you likely need, and the exact words to use when calling suppliers. Prevents the classic “I bought a regulator and now nothing fits” tragedy.
Checker
What do you have?
We’re intentionally simple here. This tool aims for “right enough to save you a wasted purchase or trip,”
not “engineering encyclopedia.”
Quick mental model
- Standard CO2 cylinders: usually CGA-320 (US). Most industrial/homebrew regulators fit these.
- SodaStream cylinders: different thread (often called TR21-4 / proprietary). Needs an adapter or specific regulator.
- Paintball bottles: yet another fitting. Policies and adapters vary; many suppliers refuse fills.
The goal is to route you to the correct “lane” and give you a call script so suppliers don’t hit you with “No” just because the question was asked in the wrong language.
Results
What likely fits / what you need
Run the checker to see results.
Safety note: Don’t “make it work” with sketchy fittings. CO2 is high-pressure.
If you’re unsure, ask the supplier or use known adapters.
FAQ
Is standard CO2 the same as SodaStream CO2?
The gas is CO2, but the cylinder valve threads usually differ.
Standard CO2 cylinders commonly use CGA-320 (US). SodaStream cylinders typically use a proprietary thread (often referenced as TR21-4).
You usually need an adapter or a SodaStream-specific regulator.
Can I refill a SodaStream cylinder at a welding shop?
Sometimes, but many will say no due to policy, fittings, or exchange-only workflows.
Calling first with the right wording saves you time.
What if I have an aquarium kit and I don’t know the fitting?
Start by identifying what cylinder you’re using (standard vs SodaStream vs paintball). Then pick the matching adapter/regulator lane.
If still unsure, contact the seller or use a known adapter kit for your cylinder type.
Can I use adapters safely?
Yes, if they’re designed for CO2 pressure and the correct thread standard.
Avoid random “close enough” fittings or DIY hacks.
Need a supplier?
Use the directory, call first, and ask using the exact wording from the tool.