Dreikantfitting, type G
Technically the same spear as type A – only with a three-lobed instead of a round body, which calls for a different coupler. That has consequences for spare parts and for conversion.
Not a system of its own, but a locking geometry
The three-lobe fitting (G-type) is often listed as a type in its own right. Technically it is not: inside it is identical to the flat fitting type A. Same housing dimension, same valve design, same opening travel – 14 mm ± 1 at the coupler, 13.5 mm at the filling and cleaning head.
The difference sits on the outside: a three-lobe housing, which calls for a differently shaped coupler. That is a locking geometry, not valve technology. It is therefore not identified with callipers but by looking from above – a photo is enough.
Because the neck is the same on both – as a rule the standard 2" × 14 TPI thread –, switching between A and G is not a modification to the keg, but a change of parts. Why the neck decides this and not the fitting.
What follows from this in practice
- Spare parts are shared. Seals, springs, circlips and valves are the same as for type A. Anyone holding both types in stock does not need a second set of parts for them.
- Couplers are not. Only a three-lobe coupler (G-type) fits a G fitting, and vice versa. That is exactly what the three-lobe shape is for.
- The washing plant stays the same. The same opening travel means no changeover and no second probe setting.
- Conversion here often means no more than swapping the head. Anyone moving a G fleet to A does not have to touch the neck. Depending on availability, replacing the fitting head is even enough – spear, spring and valve stay, because they are identical. That is the cheapest conversion there is in the keg business.
Where you will meet it
Above all on kegs from the British market. The same brewery can run flat on the Continent and three-lobe in the United Kingdom – the coupler finder carries such a case as two lines with their respective markets, instead of smoothing them into one.
Spare parts for type G
We supply seals, springs, retaining rings and valves from our EU warehouse. Retaining rings for the threadless systems always come new – they are single-use parts, not wear parts. To the spare parts overview
Length not right?
We cut spears to length. Tell us the height dimension H3 of the keg or, failing that, the design, capacity and manufacturer. Dispatch then goes out in two to three working days instead of the next day.
The statement on the technical identity of type A and type G, and the opening travels, are operating figures from Keg Exchange, not a standard. If you measure different values, write to us – we will correct them.