LEV VALVE PART, LOWER BODY, 3.0 VALVE 
This part of the 3 oz. per second valve is where the paddle arm plunger opens flow and closes flow. When the paddle plunger is seated on the raised holes in the center of the circle, it stops flow. When lifted, it opens flow down into your drinking cup. It’s signs of wear is when the circles of plastic get slightly out of round and egg shaped.