Connect CGA-320 CO2 cylinder valve to W21.8 CO2 cylinder valve
How to join 0.825"-14 NGO RH and W21.8-14 (DIN 477 / BS 341 No.8), and what stops it leaking.
Not a direct fit. Joining CGA-320 CO2 cylinder valve to W21.8 CO2 cylinder valve needs a CGA-320 to W21.8 cylinder adapter.
The two ends
- End A
- CGA-320 CO2 cylinder valve (0.825"-14 NGO RH)
- End B
- W21.8 CO2 cylinder valve (W21.8-14 (DIN 477 / BS 341 No.8))
- A seals on
- nylon or fibre washer inside the nut against the valve outlet
- B seals on
- captive O-ring or washer in the nut against the valve outlet
- Part needed
- CGA-320 to W21.8 cylinder adapter
The part to buy
CGA-320 (North America) and W21.8 (Europe, UK, Oceania) are the two CO2 cylinder outlet standards and they do not interchange. A CGA-320 to W21.8 adapter lets a US regulator run on a European cylinder, or the reverse, with the correct washer on each side.
Both connections seal on a washer inside the nut, not on tape, and both are right hand. A cross-standard adapter is a stopgap; if you are staying in one region, fit the regulator that matches your cylinder rather than stacking adapters that add two more washer joints to leak.
Related connections
Sources: CGA-320 CO2 cylinder valve outlet thread reference (0.825in-14 NGO, RH) ยท CO2Art guide to cylinder connections (CGA320, W21.8, DIN477, BS341, G5/8, TR21-4)