Post Firestone vs GAS Shutoff: specs compared
Updated 05 September 2026.
5
specs differ
Post Firestone and GAS Shutoff differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | Post Firestone | GAS Shutoff |
|---|---|---|
| Designation | 9/16"-18 UNF | 1/4" MPT x 1/4" MFL |
| Size / thread | 9/16"-18 UNF (about 14.3 mm major) | 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 | UNF male post thread | quarter-turn ball shutoff |
| Seals on | poppet inside the post; post base O-ring seals to the keg lid | NPT end taped on the thread; MFL end on the flare face |
| Rating / role | gas and liquid posts share the thread; disconnect snaps over the outside | shuts a single gas line without touching the regulator; some carry a check valve too |
Questions and answers
How do Post Firestone and GAS Shutoff compare?
Post Firestone and GAS Shutoff differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.