Ball-lock liquid disconnect (MFL) (black QD vs Tailpiece: specs compared
Updated 05 September 2026.
5
specs differ
Ball-lock liquid disconnect (MFL) (black QD and Tailpiece differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | Ball-lock liquid disconnect (MFL) (black QD | Tailpiece |
|---|---|---|
| Designation | black QD, 1/4" MFL tail | 7/8"-14 nut, 1/4" or 3/16" barb |
| Size / thread | snaps over the liquid post; 1/4" MFL (7/16-20 UNF) tail | 7/8"-14 shoulder held by a beer nut; 1/4" or 3/16" hose barb |
| Fitting form | snap-on liquid quick disconnect | barbed nipple with a shouldered nut seat |
| Seals on | O-ring over the post shoulder; flare face at the MFL tail | flat washer against the shank end under the beer nut; barb under a worm clamp on the hose |
| Rating / role | the liquid-side ball-lock disconnect, keyed to the liquid post and usually black | the piece that turns a shank thread into a hose barb for vinyl beer line |
Questions and answers
How do Ball-lock liquid disconnect (MFL) (black QD and Tailpiece compare?
Ball-lock liquid disconnect (MFL) (black QD and Tailpiece differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.