Not a direct fit. Joining Duotight ball-lock gas QD (8mm) to Cornelius corny keg post needs a Duotight gas ball-lock disconnect (snaps over the gas post). Sealing method, the real-world trap, and the exact part to buy.
Updated 05 September 2026.
Connect Duotight ball-lock gas QD (8mm) to Cornelius corny keg post
How to join grey QD, 8mm push-in tail and 19/32"-18 UNF, and what stops it leaking.
Not a direct fit. Joining Duotight ball-lock gas QD (8mm) to Cornelius corny keg post needs a Duotight gas ball-lock disconnect (snaps over the gas post).
The two ends
- End A
- Duotight ball-lock gas QD (8mm) (grey QD, 8mm push-in tail)
- End B
- Cornelius corny keg post (19/32"-18 UNF)
- A seals on
- O-ring over the post shoulder; 8mm push-in O-rings on the tube
- B seals on
- poppet inside the post; the post base O-ring seals to the keg lid
- Part needed
- Duotight gas ball-lock disconnect (snaps over the gas post)
The part to buy
The integrated Duotight gas disconnect snaps over the Cornelius gas post from the outside, so the post thread never touches your line, and its built-in 8mm push-in takes gas line directly with no flare step.
It is keyed to the gas post, so it will not seat on the liquid post; that keying is the safety feature. Reach the post through the disconnect, never by threading the post, and keep gas grey and liquid black to avoid crossing the lines.
Related connections
Questions and answers
Connect Duotight ball-lock gas QD (8mm) to Cornelius corny keg post?
Not a direct fit. Joining Duotight ball-lock gas QD (8mm) to Cornelius corny keg post needs a Duotight gas ball-lock disconnect (snaps over the gas post).