how do self-filling/gravity fed pet water bowls not overflow and spill everywhere?

Question

how do self-filling/gravity fed pet water bowls not overflow and spill everywhere?

In: 276

Answer 1

Same reason when you put your finger over the top of your straw and pull it out of your drink, the liquid doesn’t pour out of the bottom of the straw. When you block the flow of air, air can no longer replace the space that’s occupied by liquid. This creates a negative pressure zone that essentially holds the liquid in place.

With a gravity water bowl, when the bowl fills up it also blocks airs path up into the tank. This is essentially the same as putting your finger over the end of the drinking straw.