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 unitary cage body and defining a first volume;
• a second annular recess defined by a second portion of the unitary cage body, the second annular recess defining a second volume;
• one or more flow restricting passages formed through the inner wall and extending along a first axis perpendicular to the longitudinal axis;
• and
• a third annular recess defined by a third portion of the unitary cage body at a position downstream of the one or more flow restricting passages, the third annular recess defining a third volume,
• wherein the one or more flow restricting passages connect the second volume with the third volume, and
• wherein the unitary cage body further comprises an annular shoulder extending outwardly from the outer wall at a position upstream of the cage outlet, the annular shoulder arranged to directly engage a portion of the valve body to secure the unitary cage body within the valve body.

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 unitary cage body and defining a first volume;
• a second annular recess defined by a second portion of the unitary cage body spaced from the first portion of the unitary cage body along the longitudinal axis, the second annular recess defining a second volume;
• one or more flow restricting passages formed through the inner wall and extending along a first axis perpendicular to the longitudinal axis;
• and
• a third annular recess defined by a third portion of the unitary cage body spaced from the second portion of the unitary cage body along the longitudinal axis, the third annular recess defining a third volume,
• wherein the one or more flow restricting passages connect the second volume with the third volume, and
• wherein the unitary cage body further comprises an annular shoulder extending outwardly from the outer wall at a position upstream of the cage outlet, the annular shoulder arranged to directly engage a portion of the valve body to secure the unitary cage body within the valve body.

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 nonplugging 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 unitary cage body and defining a first volume;
• a second annular recess defined by a second portion of the unitary cage body, the second annular recess defining a second volume;
• one or more flow restricting passages formed through the inner wall and extending along a transverse axis perpendicular to the longitudinal axis;
• and a third annular recess defined by a third portion of the unitary cage body at a position downstream of the one or more flow restricting passages, the third annular recess defining a third volume, wherein the one or more flow restricting passages connect the second volume with the third volume, and wherein the unitary cage body further comprises an annular shoulder extending outwardly from the outer wall at a position upstream of the cage outlet, the annular shoulder arranged to directly engage a portion of the valve body to secure the unitary cage body within the valve body.