Flush valve pressure balance

摘要

A flush valve has a valve body having an inlet and an outlet. A piston is disposed in the valve body between the inlet and the outlet. A piston cap is disposed within the valve body and has a wall along which the piston is guided. A groove is disposed in the piston cap wall for equalizing pressure on sides of the piston translating therein. The groove has a shallow, semicircular shape whereby a possibility that fluid flow therethrough is diminished is minimized.

主权项

1. A flush valve, said flush valve comprising:
a valve body having an inlet and an outlet; a piston disposed in said valve body between said inlet and said outlet; a piston cap having a wall along which said piston is guided within said valve body; a cap body coupled to said piston and movable relative to said piston cap, wherein said wall defines a sliding surface for direct contact with said piston; a groove disposed in said wall for equalizing pressure on sides of said piston by allowing fluid flow around said piston and said cap body; and a wiper seal disposed upon an upper shoulder of said piston and engaging a lower surface of said cap body, said wiper seal wiping any debris in or around said groove as said piston translates in said piston cap.