Two-piece trim for use with fluid regulators

An apparatus for use with a fluid regulator, comprising:

• a first cage for controlling a flow of fluid through the fluid regulator, the first cage to provide a first flow characteristic, the first cage being interchangeable with a second cage, the second cage to provide a second flow characteristic, the first cage having a first inner wall and a first end, a first distance between facing portions of the first inner wall having a first dimension;
• and
• a first seat ring to be mounted within the fluid regulator and defining a fluid orifice, wherein the first seat ring includes a first outer wall, a second distance between opposing portions of the first outer wall having a second dimension that is larger than the first dimension of the first cage;
• and
• a second seat ring replaceable with and different from the first seat ring, wherein the second seat ring is to be removably coupled to the first cage and includes a second outer wall that is substantially similar to the first outer wall, and wherein the second seat ring provides a third fluid flow characteristic that is different than a fourth fluid flow characteristic provided by the first seat ring,
• wherein each of the first and second seat rings comprises first, second, and third annular surfaces spaced along a longitudinal axis of the regulator body that extends through the fluid orifice, the second annular surface being between the first and third annular surfaces, a first circumferential wall being between the first and second annular surfaces, a second circumferential wall being between the second and third annular surfaces, the third annular surface to be sealingly engaged by a valve plug, the first end to engage the first annular surface, the second annular surface defining a gap between the first and third annular surfaces to enable interchangeability of the first cage and the second cage.

An apparatus for use with a fluid regulator comprising:

• a plurality of different and interchangeable cages for use with the fluid regulator, wherein each of the cages has a cage interface that includes a rectangular cross-sectional shape;
• and
• a plurality of different and interchangeable seat rings for use with the fluid regulator, each of the seat rings having first, second, and third annular surfaces to be spaced along a longitudinal axis of the regulator body that extends through the fluid orifice, the second annular surface being between the first and third annular surfaces, a first circumferential wall being between the first and second annular surfaces, a second circumferential wall being between the second and third annular surfaces, the third annular surface to be sealingly engaged by a valve plug,
• wherein each of the cages is to be removably coupled to each of the seat rings such that the first circumferential wall engages or surrounds a surface of the cage interface to couple the seat rings to the cages and to align the cages with the seat rings, wherein each of the seat rings provides a different fluid flow characteristic to a fluid flowing through the fluid regulator, the second annular surface of the seat rings to define a gap between the first and third annular surfaces to enable interchangeability of the cages.

A method of coupling a two-piece trim apparatus for use with a fluid valve, the method comprising:

• selecting a first seat ring from a plurality of seat rings, each of the seat rings having first, second, and third annular surfaces spaced along a longitudinal axis of the regulator body that extends through the fluid orifice, the second annular surface being between the first and third annular surfaces, a first circumferential wall being between the first and second annular surfaces, a second circumferential wall being between the second and third annular surfaces, the third annular surface to be sealingly engaged by a valve plug;
• selecting a first cage from a plurality of cages, each of the cages having a cage interface that is to engage the seat ring interface, wherein the cage interface includes an edge to define an inner surface or wall;
• and
• coupling the first cage and the first seat ring such that the edge of the first cage engages the first annular surface,
• wherein the second annular surface defines a gap between the first and third annular surfaces to enable interchangeability of the first cage with a second cage of the plurality of cages.