Does the dip tube need to rest in the "dimple" in the bottom of the ball lock keg or should it be off to the side so the dimple can collect anything that falls out from the beer
the dip tube usually falls in the center of the dimple to dispense the entire contents of the Keg. They were designed for soda syrup, so no expected particulate was accounted for.
Dip tube goes in the middle. Interestingly enough, Ive noticed that after a keg is finished, there is a wide sediment ring around the bottom area, nowhere near the dip tube. Kinda a cool design.