GAS Checkvalve vs JG4: specs compared
Updated 05 September 2026.
6
specs differ
GAS Checkvalve and JG4 differ on 6 specs: designation, size / thread, fitting form, seals on, rating / role, tube od.
| Spec | GAS Checkvalve | JG4 |
|---|---|---|
| Designation | 1/4" FFL x 1/4" MFL | 4 mm OD |
| Size / thread | 1/4" FFL (7/16-20 UNF) inlet and 1/4" MFL (7/16-20 UNF) outlet, or barb ends | 4 mm OD tube |
| Fitting form | one-way flare check valve | push-fit collet, metric |
| Seals on | flare faces at each flare end; barb under a clamp on barb versions | single O-ring plus a stainless collet grab-ring |
| Rating / role | passes CO2 toward the keg and blocks beer or foam from returning up the gas line | John Guest Speedfit metric fittings for 4mm OD tube; tube OD must be within 0.1mm of nominal |
| Tube OD | 4 mm |
Questions and answers
How do GAS Checkvalve and JG4 compare?
GAS Checkvalve and JG4 differ on 6 specs: designation, size / thread, fitting form, seals on, rating / role, tube od.