Ball Lock Vs Pin Lock
Pin lock cornelius kegs are also known as coke kegs because this style was used exclusively by the coca cola company and use a pin lock style disconnect to connect and disconnect to the liquid and gas lines.
Ball lock vs pin lock. Pin lock are about 20 25 cheaper but have basically none of the advantages above. Pin lock disconnects use a pin to secure to the posts. Pin lock cornelius kegs. The pin lock and ball lock both refer to the way the quick disconnects attach to the cornelius keg.
The connections are different as well. For one ball lock pepsi kegs are taller with a smaller diameter while pin lock coke kegs are shorter and fatter. Both have automatic safety prv valves. Ball lock keg lids have a pull ring that allows you to manually.
Pin lock disconnects use a pin to secure to the posts. Generally speaking both ball lock and pin lock style lids are the same dimension and are interchangeable. Pin lock is shorter and larger diameter and ball lock is taller and smaller diameter. They re not interchangeable sorry.
That is sometimes a factor depending on your layout space availability. Ball lock are the accepted standard they are still made new there are a ton of parts and accessories and gadgets designed for ball lock kegs. I believe the lids are interchangeable and ball lock lids typically come with pressure relief valves. Other than that they function the same and ball lock parts tend to be more popular as noted above.
Also the pin lock keg lids have a fixed prv that seems to be an issue for some folks unless they have had a lid with a manual prv swapped as they are interchangeable. That is if the pressure gets too high both will automatically vent for safety reasons. The difference is in manual prv functionality. The disconnects are pressed on the post and the collar rotates to lock onto the pins.
A big difference are the prv pressure relief valve functions between the two styles. Ball lock disconnects use a steel ball that secures it tightly to the post.