Once someone decides that a kegging setup is right for them, the very next question is usually:

“what is the difference between ball lock and pin lock kegs?”

The answer is pretty simple. The kegs are usually quite similar, but the connection point that the gas and beer lines use is slightly different.

This is an example of a ball lock post

and this is an example of a pin lock post.

Notice the small pins that poke out of the base of the pin lock post. That is why it is named “pin lock”

History

In the past these kegs were used predominantly for soda syrup. Coke used the pin lock kegs and Pepsi used the ball lock kegs. They could have easily used the same system, but it was probably obfuscated in order to discourage restaraunt owners from switching soda companies as well as to keep the kegs circulating in their respective distribution pools.

Sizing

While easily 90% of the supply is in the standard 5 gallon size, there are also 2.5, 3, and 10 gallon kegs out there.

Dimensions

That’s not the only differences in the two kinds of kegs though. The 5 gallon pin lock kegs are generally a little bit fatter and shorter than the 5 gal ball lock ones. That can make one kind easier or harder to fit into a small fridge.

Pressure relief valve

One other difference between the two styles is that usually the pin lock kegs don’t have a manual pressure relief valve. The pressure relief valve (PRV) will release pressure when it builds up to a certain level, therefore preventing it from getting dangerously over-pressurized. Both styles of valve do this, but the Pepsi/ball lock lids have a way to pull a pin and let the gas out manually. While this is definitely a useful thing it can also be done on the pin lock keg by pressing on the gas in line with your fingernail or a screwdriver.

Pricing

Due to the general preference for ball lock kegs, they command a premium over pin lock kegs. Sometimes as much as $20 difference on a used keg. It is also very difficult to find new pin lock kegs. Click here to check pricing on pin lock and Here to check pricing on ball lock.

“Regardless of your preference in keg styles, most people agree that getting all of one kind is better than a mishmash. You will need to buy twice as many disconnects if you have both styles in your supply.”

Recommendation

I recommend that people getting in to kegging for the first time go with pin lock. Kegs are getting more and more expensive as the supply continues to dry up. Saving $10 to $20 per keg can add up pretty quickly, and since they are in lower demand you can sometimes score incredible bargains. At the time of this writing, Adventures in Homebrewing has 4 3 gallon kegs for $125, and 4 5 gallon kegs for $139. You CAN NOT beat those prices unless you score an amazing craigslist deal.

If you have ended up with a bunch of different styles of keg, no worries! I’ve done a tutorial on how to convert Pin Lock to Ball lock and vice versa.