Patent ID: 7815164

Claim:
A low noise valve assembly of the type used to control the flow of gases through a conduit while mitigating noise induced by near sonic gas flow encountering stagnant flow in the region of the valve, said assembly comprising: an inlet tube terminating in a chamber; an outlet tube having a generally annular valve seat disposed within said inlet tube chamber and a flow channel extending through said valve seat, said flow channel having a minimum throat diameter (T) immediately downstream of said valve seat; a valve disposed in said inlet tube chamber for movement toward and away from a closed condition in direct contact with said valve seat; said valve including an insert body spatially segregated from direct contact with said outlet tube while partially filling said flow channel when said valve is in said closed condition, said insert body having a generally circular base with a diameter (D), said base diameter (D) being larger than said throat diameter (T) wherein insert body extends from said base toward a downstream terminal tip, with the normal distance (H) between said base and said tip controlled by the relationship: 1.0≦D/H≦2.0, where D is the diameter of said base and H is the normal distance between said base and said tip; wherein said outlet tube includes a radius of curvature forming a transition between said valve seat and said flow channel, said radius of curvature (R) controlled by the relationship: 0.3≦R/H≦1.5.