The difference between the System “D” coupler and the System “S” coupler lies mainly in the length of the probe. While they are both European keg couplers, the System “S” coupler has a longer probe compared to the System “D” coupler.
The System “D” coupler is a common type of European keg coupler that is widely used in many countries. It is designed to connect to kegs that use the “D” system valve. The “D” system valve is characterized by its two flat depressions on the valve, which allows for a secure connection between the keg and the coupler. The probe of the System “D” coupler is shorter in length, typically around 1.2 inches, which is suitable for most kegs that use this system.
On the other hand, the System “S” coupler is a variant of the System “D” coupler with a longer probe. This longer probe is specifically designed to accommodate kegs that have a deeper valve seating, such as certain European beers. The System “S” coupler has a probe length of around 2.2 inches, which allows for a proper connection to these kegs.
One example where the difference between the System “D” and System “S” couplers becomes apparent is when dealing with European beers that are packaged in larger kegs known as Grundy kegs. These kegs, which are often used for beers like Bass, Watneys, and some Irish brews, require the use of the System “G” or Grundy keg coupler. The System “G” coupler is completely different from both the System “D” and System “S” couplers and is specifically designed for these types of kegs.
The main difference between the System “D” and System “S” couplers is the length of the probe. The System “S” coupler has a longer probe compared to the System “D” coupler, allowing it to properly connect to kegs with deeper valve seating. It is important to use the appropriate coupler for each keg system to ensure a proper and secure connection.