Whether it’s a quick stop-off on a summery walk for a fresh pint, or a glass of wine in the evening with friends, a visit to the pub is one of life’s great pleasures. 

From the pub’s perspective, supplying customers with high-quality beverages, accompanied by excellent service, is therefore key to ensuring they keep coming back. However, serving drinks isn’t as simple as just pouring them — a lot goes on behind the scenes. There’s a technical process involved with providing fresh beverages, especially if liquids are stored and dispensed from kegs. 

One of the main components involved in this particular process is a keg coupler, a key that helps get alcohol from a keg to the tap. In order to keep the show on the road, pubs and other hospitality business owners therefore need to be acquainted with the keg couplers. Here we’re going to look at how they work, why exactly you need them and the different types of key couplers available.

How does a keg coupler work

A keg coupler attaches to the fitting/valve at top of your keg, enabling pressurised gas to flow into the side of it through an air line from a CO2 or nitrogen tank. Think of the keg coupler as the key, and the fitting valve as the lock. This forces air into the keg which then allows beer to flow out through the beer line (this is essentially a tube that runs from the keg to the tap), producing a fresh pint. 

Remember that your keg coupler needs to be the correct type to fit the valve. This video shows you how to connect a type A coupler to a Petainer keg, for instance.

Why do you need keg couplers

Keg couplers are an essential component of the beverage delivery process, enabling you to serve customers exactly what they want — a perfectly chilled, delicious drink. When connected to the keg’s valve, the components work together to ensure this process happens. 

It’s imperative you use the right keg coupler though, otherwise your staff may not even be able to pour drinks. So, to keep your customers happy, the transfer from draught tap to glass needs to be flawless, and the keg coupler is a vital part of that process.

A, S, D & G fittings on Petainer Kegs

The different types of keg couplers

There are common coupler types that can be used for a variety of keg styles and drinks. Many of these have been manufactured independently by specific beer and beverage companies. All keg couplers are similar in appearance and function, however, you must have the right one in order for your keg delivery system to work correctly. Keg couplers are designed specifically for certain types of valves, meaning there isn’t a one-size-fits-all approach. Petainer Kegs come with standard fitting types A,S,D and G meaning that no specialised equipment is needed to be able to dispense.

A coupler

Less commonly used in the UK, the A type fits most German keg valves and is suitable for Guinness, Hoegarden and Pimms.

D coupler

The D type is designed to fit most US Sankey keg valves for beverages such as Corona, Coors and Budweiser.

G coupler

This fits some European keg valves and is used for beers like Carling, Tennent’s and Old Speckled Hen.

S coupler

Commonly used in the UK, the S coupler is designed for leading brands including Carlsberg, Strongbow and Kronenburg.

The keg coupler you require depends on the brand and style of beer (or other compatible beverages) you serve. As you can see, each keg coupler is suitable for a specific brand or country of manufacture. The American Sankey D coupler, for example, is the most popular for US beers. It fits all domestic brand kegs and 95% of all beers produced in the country. So, if you offer customers Coors, Budweiser or Goose Island, for instance, you’ll need the D coupler.

Petainer Kegs

Our 15L, 20L and 30L Hybrid Kegs are compatible with A, D, G and S type couplers, as are our Classic Kegs. These are suitable for most of the existing filling and tapping systems available on the market. Since there are a variety of keg coupler types available, it makes transitioning to a new keg brand simple and quick as the couplers suit many different types. This means you won’t incur any additional costs as a result.


If you need any extra guidance on kegs and its accompanying coupler, get in touch with us and we’ll be able to discuss your requirements.