Patent attributes
A control valve has a body having an inlet and outlet, a valve seat between the inlet and outlet, a valve plug, and a cage adjacent the valve seat to provide guidance for the valve plug. The valve plug is movable between a closed position, where the valve plug sealingly engages the valve seat, and an open position, where the valve plug is spaced away from the valve seat. The cage has a circumferential wall having inner and outer surfaces and a plurality of passages formed through the wall. Each passage can have a first portion extending from the inner surface and a second portion extending from the outer surface, where the second portion has a diameter smaller than that of the first portion, can follow a non-linear path from the inner to outer surface, and/or can have a cross-sectional area that varies from the inner to outer surface.