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A fluid control valve includes a valve body having a fluid passageway, a cage mounted in the fluid passageway, the cage including a wall defining a cage bore having an axis, and a valve plug assembly including a valve plug that is axially slidable in the cage bore. The cage defines one or more windo

A fluid control valve includes a valve body having a fluid passageway, a cage mounted in the fluid passageway, the cage including a wall defining a cage bore having an axis, and a valve plug assembly including a valve plug that is axially slidable in the cage bore. The cage defines one or more windows and a valve seat. Each of the one or more windows includes a plurality of slots each having a longitudinal axis. The longitudinal axis of each of the slots is parallel to or tilted at a relatively small angle with respect to a reference plane that is perpendicular to the cage bore axis. The longitudinal axes of the slots are preferably oriented at an angle of about 0° to 15° with respect to the reference plane.

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1. A fluid control valve comprising:a valve body having a fluid passageway;a cage mounted in said fluid passageway, said cage including a wall defining a cage bore having an axis, said cage defining one or more windows and a valve seat, each of said one or more windows comprising a plurality of slot

1. A fluid control valve comprising:a valve body having a fluid passageway;a cage mounted in said fluid passageway, said cage including a wall defining a cage bore having an axis, said cage defining one or more windows and a valve seat, each of said one or more windows comprising a plurality of slots each having a longitudinal axis, wherein the longitudinal axis of each of said slots is parallel to or tilted at a relatively small angle with respect to a reference plane that is perpendicular to the cage bore axis, said slots being axially spaced apart, wherein said slots in adjacent windows are tilted in opposite directions with respect to said reference plane; anda valve plug assembly comprising a valve plug that is axially slidable in the cage bore. 2. A fluid control valve as defined in claim 1, wherein the longitudinal axes of said slots are oriented at an angle in a range of about 0° to 15° with respect to the reference plane. 3. A fluid control valve as defined in claim 1, wherein the longitudinal axes of said slots are tilted at an angle of about 4° with respect to the reference plane. 4. A fluid control valve as defined in claim 1, wherein the slots of each window are parallel to each other. 5. A fluid control valve as defined in claim 1, wherein two or more of said slots have different lengths. 6. A fluid control valve as defined in claim 1, wherein said slots are relatively short in a portion of said cage adjacent to the valve seat and are relatively long in a portion of said cage spaced from said valve seat. 7. A fluid control valve as defined in claim 1, wherein said slots have a width at an inside surface of the wall in a range of about 1% to 5% of the diameter of said cage bore. 8. A fluid control valve as defined in claim 1, wherein said slots are tilted at an angle with respect to the reference plane to provide a relatively smooth flow progression between adjacent slots as a function of valve plug position along the cage bore axis. 9. A fluid control valve as defined in claim 1, wherein said slots are tapered in width through the wall of said cage. 10. A fluid control valve as defined in claim 1, wherein said slots increase in width with increasing radius through the wall of said cage. 11. A fluid control valve as defined in claim 10, wherein said slots are tapered in width through the wall of said cage at an angle in a range of about 4° to 17°. 12. A fluid control valve as defined in claim 1, wherein said slots are configured for low noise liquid flow toward said cage bore axis and for low noise gas flow away from said cage bore axis. 13. A fluid control valve as defined in claim 1, wherein said slots are configured for an equal percent flow characteristic as a function of valve plug position. 14. A fluid control valve as defined in claim 1, wherein said valve plug has a seating surface for engaging the valve seat of said cage, and wherein the radial thickness of said valve plug in close proximity to said valve seat is configured to limit exposure of the valve plug to imploding jets when liquid flow into the cage is undergoing cavitation. 15. A fluid control valve as defined in claim 1, wherein the radial thickness of said valve plug is less than three times the width of said slots. 16. A fluid control valve as defined in claim 1, wherein said cage defines a sealing lip in the cage bore located above said one or more windows and wherein said valve plug includes one or more pressure balancing passages between opposite ends thereof, said valve plug assembly further comprising an elastomer ring for engaging the sealing lip when the valve plug is in a closed position. 17. A fluid control valve as defined in claim 1, wherein said cage defines a sealing lip located in the cage bore above said one or more windows and wherein said valve plug assembly further comprises a deformable sealing ring for engaging the sealing lip when the valve plug is in a closed position. 18. A valve cage for mounti ng in a fluid passageway of a fluid control valve, comprising:a generally cylindrical wall defining a cage bore having an axis, said wall defining at least one window and a valve seat, said at least one window comprising a plurality of slots each having a longitudinal axis, wherein the longitudinal axis of each of said slots is parallel to or tilted at a relatively small angle with respect to a reference plane that is perpendicular to the cage bore axis, said slots being axially spaced apart, wherein said slots in adjacent windows are tilted in opposite directions with respect to said reference plane. 19. A valve cage as defined in claim 18, wherein the longitudinal axes of said slots are oriented at an angle in a range of about 0° to 15° with respect to the reference plane. 20. A valve cage as defined in claim 18, wherein two or more of said slots have different lengths. 21. A valve cage as defined in claim 18, wherein said slots are relatively short in a portion of said cage adjacent to said valve seat and are relatively long in a portion of said cage spaced from said valve seat. 22. A valve cage as defined in claim 18, wherein said slots are tapered in width through the wall of said cage. 23. A valve cage as defined in claim 18, wherein said slots increase in width with increasing radius through the wall of said cage. 24. A fluid control valve as defined in claim 23, wherein said slots are tapered in width through the wall of said cage at angles in a range of about 4° to 17°.