Bs341 8 vs Ball-lock gas disconnect (MFL: specs compared
Updated 05 September 2026.
5
specs differ
Bs341 8 and Ball-lock gas disconnect (MFL differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | Bs341 8 | Ball-lock gas disconnect (MFL |
|---|---|---|
| Designation | W21.8 (British designation) | grey QD, 1/4" MFL tail |
| Size / thread | 21.8 mm x 14 TPI right hand, external (the W21.8 thread) | snaps over the gas post; 1/4" MFL (7/16-20 UNF) tail, often with an integrated check valve |
| Fitting form | cylinder valve outlet nut, external | snap-on gas quick disconnect |
| Seals on | captive O-ring or washer in the nut against the valve outlet | O-ring over the post shoulder; flare face at the MFL tail |
| Rating / role | the British Standard 341 designation for the CO2 cylinder outlet used across the UK | the gas-side ball-lock disconnect, keyed to the gas post and usually grey or white |
Questions and answers
How do Bs341 8 and Ball-lock gas disconnect (MFL compare?
Bs341 8 and Ball-lock gas disconnect (MFL differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.