Not compatible. Duotight ball-lock gas QD (8mm) and Ball-lock gas disconnect (MFL, check 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 Duotight ball-lock gas QD (8mm) to Ball-lock gas disconnect (MFL, check valve)
How to join grey QD, 8mm push-in tail and grey QD, 1/4" MFL tail, and what stops it leaking.
Not compatible. Duotight ball-lock gas QD (8mm) and Ball-lock gas disconnect (MFL, check 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
- Duotight ball-lock gas QD (8mm) (grey QD, 8mm push-in tail)
- End B
- Ball-lock gas disconnect (MFL, check valve) (grey QD, 1/4" MFL tail)
- A seals on
- O-ring over the post shoulder; 8mm push-in O-rings on the tube
- B seals on
- O-ring over the post shoulder; flare face at the MFL tail
- Part needed
- matched replacement, no adapter exists
The part to buy
A Duotight-integrated gas disconnect and an MFL-tail gas disconnect do the same job on the gas post but end differently: one takes push-in line directly, the other needs an FFL swivel or push-in flare fitting on its MFL tail. Pick one style by the line you run.
Both are keyed to the gas post, so they are interchangeable on the keg; the difference is the tail. If you run push-in line, the integrated Duotight version saves a fitting; if you run flare line, the MFL-tail version is the one to buy.
Related connections
Questions and answers
Connect Duotight ball-lock gas QD (8mm) to Ball-lock gas disconnect (MFL, check valve)?
Not compatible. Duotight ball-lock gas QD (8mm) and Ball-lock gas disconnect (MFL, check valve) do not share a mating thread, so there is no adapter between them; fit the part that matches your hardware.