Control valves and cages that are adapted to reduce flashing and cavitation

A control valve, comprising:

• a valve body having an inlet, an outlet, and defining a flow passage between the inlet and the outlet;
• an orifice disposed in the flow passage and having a valve seat;
• a generally cylindrical cage being disposed within the valve body and having a central bore, an upper portion, and a lower portion, the lower portion seated against the valve seat;
• a control element slidably received in the central bore of the cage and being shiftable between a closed position in which the control element is seated against the valve seat thereby preventing flow though the orifice, and an open position in which the control element is spaced away from the valve seat thereby permitting flow through the orifice;
• wherein the cage includes an inner wall, an outer wall, and an intermediate wall disposed between the inner wall and the outer wall, the inner wall and the outer wall extending from the upper portion of the cage, the intermediate wall extending from the lower portion of the cage and comprising a base portion coupled to the lower portion of the cage and a terminal portion, a contiguous-annular surface of the intermediate wall extending from the lower portion of the cage on a first side of the intermediate wall, past the terminal portion, and to the base portion on a second side of the intermediate wall;
• the inner wall including an inlet opening and the outer wall including an outlet opening;
• and
• the inner wall, the outer wall, and the intermediate wall cooperating to define a portion of the flow passage, the portion of the flow passage extending from the inlet opening to the outlet opening,
• wherein the portion of the flow passage further extends from the inlet opening, between the inner wall and the intermediate wall, past the terminal portion of the intermediate wall and between the terminal portion and the upper portion of the cage, between the intermediate wall and the outer wall, to the outlet opening,
• wherein at least one of the inner wall and the outer wall includes a plurality of protrusions extending into the portion of the flow passage, and wherein the intermediate wall includes a plurality of protrusions extending into the portion of the flow passage.