Restrictor Plate vs Tr21: specs compared
Updated 05 September 2026.
5
specs differ
Restrictor Plate and Tr21 differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | Restrictor Plate | Tr21 |
|---|---|---|
| Designation | 5-hole restrictor plate | TR21x4 (soda / SodaStream-style) |
| Size / thread | internal disc, typically with five small holes, sized to the stout faucet body | TR21 x 4 mm pitch trapezoidal |
| Fitting form | internal flow-restricting disc | trapezoidal cylinder valve, external |
| Seals on | sits captive inside the stout faucet, not a threaded joint | O-ring on the valve stem |
| Rating / role | the part that de-gasses nitro beer as it is forced through its small holes | small refillable soda-maker CO2 cylinders |
Questions and answers
How do Restrictor Plate and Tr21 compare?
Restrictor Plate and Tr21 differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.