Patent ID: 7137612

Claim:
A valve comprising: a valve body that includes an inlet passage that forms an inlet port, an outlet passage that forms an outlet port, and a plenum; an internal valve trim defining an inner surface that defines an internal passage for connecting the plenum to the outlet port, the inner surface including a first surface that defines a valve seat and an opening having an average diameter; and a valve poppet that is moveably positioned at least partially within the internal passage, the valve poppet including an outer surface that includes a complementary surface for mating with the valve seat and substantially closing the internal passage when the valve is in a closed position, the outer surface of the valve poppet further including a distal portion located downstream of the complementary surface, the distal portion tapering from a first section having a first cross-sectional area to a second section having a second cross-sectional area, the second cross-sectional area being less than 25% of the first cross-sectional area and the second section being located a distance that is at least twice the average diameter of the opening downstream of the first section; wherein the distal portion of the valve poppet is defined by an outer surface that curves with respect to a longitudinal axis of the valve poppet, the outer surface including a convex portion and a concave portion and wherein the convex portion is located downstream of the concave portion.