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Connect Cornelius corny keg post to MFL male flare (1/4")

How to join 19/32"-18 UNF and 1/4" MFL (7/16"-20 UNF), and what stops it leaking.

End ACornelius corny keg post (19/32"-18 UNF)Needs an adapterEnd BMFL male flare (1/4") (1/4" MFL (7/16"-20 UNF))

Not a direct fit. Joining Cornelius corny keg post to MFL male flare (1/4") needs a ball-lock disconnect with a 1/4 MFL tail.

The two ends

End A
Cornelius corny keg post (19/32"-18 UNF)
End B
MFL male flare (1/4") (1/4" MFL (7/16"-20 UNF))
A seals on
poppet inside the post; the post base O-ring seals to the keg lid
B seals on
metal 45 degree flare face, never PTFE tape
Part needed
ball-lock disconnect with a 1/4 MFL tail

The part to buy

You never thread onto a corny post directly. A ball-lock disconnect snaps over the post and carries a 1/4 MFL flare tail, which then joins your flare gas or liquid line. So a corny keg reaches an MFL system through the disconnect, not an adapter on the post.

Gas and liquid disconnects are keyed differently and often colour coded, grey or white for gas, black for liquid. Fitting the liquid disconnect to the gas post is possible with force and will push beer up your gas line. Match disconnect to post duty.

Related connections

Sources: Homebrew Finds: corny keg post thread sizes (ball lock and pin lock) · 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