Inline gas shutoff valve: 1/4" MPT (1/4-18 NPT) one end, 1/4" MFL (7/16-20 UNF) the other, often with a check valve, quarter-turn ball shutoff, seals on NPT end taped on the thread; MFL end on the flare face. What it fits and the adapters to join it to other keg fittings.
Updated 05 September 2026.
Inline gas shutoff valve (1/4" MPT x 1/4" MFL)
Where 1/4" MPT x 1/4" MFL is used, its real dimensions, and how to connect it to other keg fittings.
Published dimensions
- Designation
- 1/4" MPT x 1/4" MFL
- Size / thread
- 1/4" MPT (1/4-18 NPT) one end, 1/4" MFL (7/16-20 UNF) the other, often with a check valve
- Fitting form
- quarter-turn ball shutoff
- Seals on
- NPT end taped on the thread; MFL end on the flare face
- Rating / role
- shuts a single gas line without touching the regulator; some carry a check valve too
Used on: isolating one keg's gas line so it can be disconnected without depressurising the whole system.
A gas shutoff lets you close one keg's gas without shutting the regulator. The common homebrew version is 1/4 MPT (NPT) on one side and 1/4 MFL flare on the other, so the NPT end is taped and the flare end is not. A version with a 5/16 barb outlet instead takes gas line under a clamp.
Flare fittings seal on the 45 degree flare face and must never be taped. Push-in fittings seal on an O-ring against the tube wall and need the tube cut square. Barbs seal under a worm clamp. Getting the sealing method right matters more than the thread label, because most homebrew leaks are a taped flare or an unclamped barb.
Connect this fitting
Questions and answers
What is the designation of the Inline gas shutoff valve (1/4" MPT x 1/4" MFL)?
1/4" MPT x 1/4" MFL
What is the size / thread of the Inline gas shutoff valve (1/4" MPT x 1/4" MFL)?
1/4" MPT (1/4-18 NPT) one end, 1/4" MFL (7/16-20 UNF) the other, often with a check valve
What is the fitting form of the Inline gas shutoff valve (1/4" MPT x 1/4" MFL)?
quarter-turn ball shutoff
What is the seals on of the Inline gas shutoff valve (1/4" MPT x 1/4" MFL)?
NPT end taped on the thread; MFL end on the flare face