Patent ID: 8899551

Claim:
A valve assembly comprising: a valve body having an inlet, an outlet, a passageway between the inlet and the outlet, and an annular body recess formed on a top portion of the valve body, the body recess including a body mating surface; a bonnet removably secured to the top portion of the valve body, the bonnet having an annular bonnet recess formed on a bottom portion of the bonnet, the bonnet recess including a bonnet mating surface; a valve cage disposed at least partially within the passageway, the valve cage having an elongated body portion extending along a longitudinal axis and having an outer surface, the valve cage also having a circumferential mating protrusion extending from the outer surface along a transverse plane that is normal to the longitudinal axis, the mating protrusion including an upper mating surface and a lower mating surface, wherein the upper mating surface of the mating protrusion is disposed within the bonnet recess such that the upper mating surface is aligned with and adjacent to the bonnet mating surface, wherein the lower mating surface of the mating protrusion is disposed within the body recess such that the lower mating surface is aligned with and adjacent to the body mating surface, and wherein the upper mating surface and the lower mating surface of the mating protrusion either both converge or both diverge towards the transverse plane as the upper mating surface and the lower mating surface extend away from the longitudinal axis.