Connect Cornelius pin-lock keg post to MFL male flare (1/4")
How to join 19/32"-18 UNF (both posts) and 1/4" MFL (7/16"-20 UNF), and what stops it leaking.
Not a direct fit. Joining Cornelius pin-lock keg post to MFL male flare (1/4") needs a pin-lock disconnect with a 1/4 MFL tail.
The two ends
- End A
- Cornelius pin-lock keg post (19/32"-18 UNF (both posts))
- End B
- MFL male flare (1/4") (1/4" MFL (7/16"-20 UNF))
- A seals on
- poppet inside the post; post base O-ring seals to the keg lid
- B seals on
- metal 45 degree flare face, never PTFE tape
- Part needed
- pin-lock disconnect with a 1/4 MFL tail
The part to buy
A pin-lock corny keg reaches an MFL flare line the same way a ball-lock one does: through the disconnect, not the post. A pin-lock disconnect drops over the post, locks on its pins, and carries a 1/4 MFL tail for your flare gas or liquid line.
Gas and liquid pin-lock disconnects differ by how many pins they clear, two for gas and three for liquid, so they only fit their own post. Forcing the wrong one is what sends beer up the gas line. Match disconnect duty to the post.
Related connections
Sources: Homebrew Finds keg post thread size reference (per-maker gas/liquid threads) · Beer Maverick: swapping pin lock corny kegs to ball locks (post threads) · MoreFlavor thread types explained (MFL/FFL, NPT, BSP) · KegLand Duotight 9.5mm x FFL (7/16-20 UNF, 1/4 SAE) product data · SAE J512 45 degree SAE flare (7/16-20 UNF) fitting reference