Not compatible. CGA-320 CO2 cylinder valve and CGA-326 nitrous oxide 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 CGA-320 CO2 cylinder valve to CGA-326 nitrous oxide valve
How to join 0.825"-14 NGO RH and 0.825"-14 NGO RH, round seat, and what stops it leaking.
Not compatible. CGA-320 CO2 cylinder valve and CGA-326 nitrous oxide 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
- CGA-320 CO2 cylinder valve (0.825"-14 NGO RH)
- End B
- CGA-326 nitrous oxide valve (0.825"-14 NGO RH, round seat)
- A seals on
- nylon or fibre washer inside the nut against the valve outlet
- B seals on
- washer against a round nipple seat
- Part needed
- matched replacement, no adapter exists
The part to buy
CGA-320 (CO2, flat seat) and CGA-326 (nitrous oxide, round seat) share the 0.825-14 thread but differ in seat shape, so a CO2 regulator nut can start on a nitrous valve and then fail to seal or seal on the wrong gas. There is no safe adapter; nitrous oxide is not a beverage gas.
The shared thread is a hazard, not a convenience. Read the CGA number and gas on the cylinder before connecting a regulator, and never run a CO2 regulator on a nitrous (326) cylinder to force a fit.
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Questions and answers
Connect CGA-320 CO2 cylinder valve to CGA-326 nitrous oxide valve?
Not compatible. CGA-320 CO2 cylinder valve and CGA-326 nitrous oxide valve do not share a mating thread, so there is no adapter between them; fit the part that matches your hardware.