Not compatible. Mini CO2 regulator (cartridge) and CGA-320 CO2 cylinder valve do not share a mating thread, so there is no adapter between them; fit the part that matches your hardware. Sealing method, the real-world trap, and the exact part to buy.
Updated 05 September 2026.
Connect Mini CO2 regulator (cartridge) to CGA-320 CO2 cylinder valve
How to join 5/8-18 inlet, 1/4" MFL out and 0.825"-14 NGO RH, and what stops it leaking.
Not compatible. Mini CO2 regulator (cartridge) and CGA-320 CO2 cylinder valve do not share a mating thread, so there is no adapter between them; fit the part that matches your hardware.
The two ends
- End A
- Mini CO2 regulator (cartridge) (5/8-18 inlet, 1/4" MFL out)
- End B
- CGA-320 CO2 cylinder valve (0.825"-14 NGO RH)
- A seals on
- cartridge seat at the inlet; flare face at the outlet
- B seals on
- nylon or fibre washer inside the nut against the valve outlet
- Part needed
- matched replacement, no adapter exists
The part to buy
A mini cartridge regulator has a 5/8-18 cartridge inlet, not a CGA-320 nut, so it does not thread onto a refillable CGA-320 cylinder. For a refillable tank you use a full CGA-320 regulator; the mini one is for 74g cartridges only.
Do not try to adapt a cartridge regulator onto a big tank; the inlet is the wrong thread and the regulator is sized for cartridge duty. Pick the regulator by the gas source, a CGA-320 one for tanks, a 5/8-18 one for 74g cartridges.
Related connections
Questions and answers
Connect Mini CO2 regulator (cartridge) to CGA-320 CO2 cylinder valve?
Not compatible. Mini CO2 regulator (cartridge) and CGA-320 CO2 cylinder valve do not share a mating thread, so there is no adapter between them; fit the part that matches your hardware.