FFL vs GAS Checkvalve: specs compared
Updated 05 September 2026.
5
specs differ
FFL and GAS Checkvalve differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | FFL | GAS Checkvalve |
|---|---|---|
| Designation | 1/4" FFL (7/16"-20 UNF) | 1/4" FFL x 1/4" MFL |
| Size / thread | 7/16"-20 UNF female thread, 45 degree flare seat | 1/4" FFL (7/16-20 UNF) inlet and 1/4" MFL (7/16-20 UNF) outlet, or barb ends |
| Fitting form | SAE 45 degree flare, female | one-way flare check valve |
| Seals on | mates against a male 45 degree flare face | flare faces at each flare end; barb under a clamp on barb versions |
| Rating / role | the female half of the homebrew flare standard | passes CO2 toward the keg and blocks beer or foam from returning up the gas line |
Questions and answers
How do FFL and GAS Checkvalve compare?
FFL and GAS Checkvalve differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.