Monolithic, Non-Plugging Multi-Stage Valve Trim

A non-plugging, multi-stage valve trim adapted to be disposed in a valve body of a fluid flow control device, the valve trim comprising:

• a unitary cage body extending along a longitudinal axis;
• and
• a valve plug movably disposed within the unitary cage body to control fluid flow through the unitary cage body,
• wherein the unitary cage body comprises an outer wall arranged to engage the valve body, an inner wall spaced radially inwardly of the outer wall, a cage inlet formed in the unitary cage body, a cage outlet formed in the outer wall, and a pressure reducing fluid flow passageway formed within the unitary cage body and extending between the cage inlet and the cage outlet, the pressure reducing fluid flow passageway defined by:
• a first annular recess defined by a first portion of the outer wall and defining a first volume;
• a second annular recess defined by a second portion of the outer wall, the second annular recess defining a second volume;
• and
• one or more flow restricting passages formed in the inner wall and extending along a first axis perpendicular to the longitudinal axis, wherein the one or more flow restricting passages connect the first volume with the second volume.

A fluid flow control device, comprising:

• a valve body comprising a valve body inlet, a valve body outlet, and a passageway extending between the valve body inlet and the valve body outlet;
• a non-plugging multi-stage valve trim at least partially disposed in the passageway of the valve body, the valve trim comprising:
• a unitary cage body extending along a longitudinal axis;
• and
• a valve plug movably disposed within the unitary cage body to control fluid flow through the passageway of the valve body,
• wherein the unitary cage body comprises an outer wall engaging the valve body, an inner wall spaced radially inwardly of the outer wall, a cage inlet formed in the unitary cage body and in fluid communication with the valve body inlet, a cage outlet formed in the outer wall and in fluid communication with the valve body outlet, and a multi-stage pressure reducing fluid flow passageway formed within the unitary cage body and extending between the cage inlet and the cage outlet, the multi-stage pressure reducing fluid flow passageway defined by:
• a first annular recess defined by a first portion of the outer wall and defining a first volume;
• a second annular recess defined by a second portion of the outer wall spaced from the first portion of the outer wall along the longitudinal axis, the second annular recess defining a second volume;
• and
• one or more flow restricting passages formed in the inner wall and extending along a first axis perpendicular to the longitudinal axis, wherein the one or more flow restricting passages connect the first volume with the second volume.

A method of manufacturing, comprising:

• creating a non-plugging multi-stage valve cage adapted to be disposed in a valve body of a fluid flow control device using an additive manufacturing technique, wherein the non-plugging multi-stage valve cage comprises a unitary cage body extending along a longitudinal axis and comprising an outer wall arranged to engage the valve body and an inner wall spaced radially inwardly of the outer wall, a cage inlet formed in the unitary cage body, a cage outlet formed in the outer wall, and a pressure reducing fluid flow passageway formed within the unitary cage body and extending between the cage inlet and the cage outlet, the pressure reducing fluid flow passageway defined by:
• a first annular recess defined by a first portion of the outer wall and defining a first volume;
• a second annular recess defined by a second portion of the outer wall, the second annular recess defining a second volume;
• and one or more flow restricting passages formed in the inner wall and extending along a transverse axis perpendicular to the longitudinal axis, wherein the one or more flow restricting passages connect the first volume with the second volume.