How to join 1/4" FFL x 1/4" MFL and grey QD, 1/4" MFL tail, and what stops it leaking.
Updated 05 September 2026.
Connect Inline gas check valve to Ball-lock gas disconnect (MFL, check valve)
How to join 1/4" FFL x 1/4" MFL and grey QD, 1/4" MFL tail, and what stops it leaking.
These connect directly. Inline gas check valve mates with Ball-lock gas disconnect (MFL, check valve) without an adapter.
The two ends
- End A
- Inline gas check valve (1/4" FFL x 1/4" MFL)
- End B
- Ball-lock gas disconnect (MFL, check valve) (grey QD, 1/4" MFL tail)
- A seals on
- flare faces at each flare end; barb under a clamp on barb versions
- B seals on
- O-ring over the post shoulder; flare face at the MFL tail
- Part needed
- none, direct fit
A gas check valve feeds straight into a gas ball-lock disconnect: the check valve's MFL outlet meets the disconnect's FFL, or the disconnect's own integrated check valve does the job and no separate valve is needed.
Do not stack two check valves in series without reason; one on the line or built into the disconnect is enough, and each adds a small pressure drop. Confirm whether your gas disconnect already has a check valve before adding another.
Related connections
Questions and answers
Connect Inline gas check valve to Ball-lock gas disconnect (MFL, check valve)?
These connect directly. Inline gas check valve mates with Ball-lock gas disconnect (MFL, check valve) without an adapter.