Ball cage insert with reduced wear, reduced pressure drop, and enhanced performance characteristics
A ball valve cage insert that includes: (1) a first section including an inlet ring having a radial wall thickness varies along the longitudinal axis of the cage; (2) a second section including side ribs that define a plurality of side openings, where the width of each opening varies from a first width at a first radial distance from the longitudinal axis to a second width at a second radial distance and (3) a third section including closure ribs extending from a first point at a first radial distance from the longitudinal axis to a second point where, as measured at a given radial distance from the longitudinal axis, the width of each closure rib varies from a first circumferential width at a first point on the longitudinal axis to a second width at a second point on the longitudinal axis.
1. A ball valve cage comprising:
a lower ring defining generally circular inlet opening, the generally circular inlet opening defining a center point through which a longitudinal axis passes; and
a plurality of side ribs, each side rib having a longitudinal length and extending longitudinally from the lower ring, each side rib having an inner surface and an outer surface, wherein the inner surface is radially closer to the longitudinal axis than the outer surface, each side rib defining an angular span with respect to the longitudinal axis; and
wherein, along at least a majority of longitudinal length of the side ribs, the angular span of each of the side ribs as measured with respect to the longitudinal axis at the inner surface of the rib is the same as the angular span of each side rib as measured with respect to the longitudinal axis at the outer surface of the rib; and
wherein for at least a first point along the longitudinal axis, lines passing along the sides of the plurality of side ribs will intersect at a common point on the longitudinal axis.
2. The cage of claim 1 wherein the side ribs define side surfaces, and wherein, across a first longitudinal expanse, the side surfaces of the side ribs are flat and wherein, across a second longitudinal expanse, the side surfaces of the ribs are curved.
3. The cage of claim 2 in combination with a sucker rod pump cage, wherein the ball valve cage is positioned within a cavity within the sucker rod pump cage and wherein the interior cavity of the sucker rod pump cage is formed to define a plurality of recessed areas through which fluid can pass.
4. The cage of claim 1 , wherein the side ribs collectively define a plurality of openings through which fluid can pass out of the cage and wherein, along a given plane passing normally through the longitudinal axis, the circumferential width of each opening defined by the side ribs at a first radial distance from the longitudinal axis varies from the circumferential width of such opening at a second radial distance from the longitudinal axis.