초록 ▼

A trim assembly for a control valve includes a seal for sealing a leak path, where the seal is provided to perform advantageously in high-temperature applications, e.g., applications including temperatures of at least 450° F. (232.22° C.). The control valve comprises a valve body and contr

A trim assembly for a control valve includes a seal for sealing a leak path, where the seal is provided to perform advantageously in high-temperature applications, e.g., applications including temperatures of at least 450° F. (232.22° C.). The control valve comprises a valve body and control element. The control element is disposed within the valve body for controlling the flow of fluid therethrough. The trim assembly comprises a valve seat and a retention ring. The valve seat is fixed to the valve body, and the retention ring is threadably connected to the valve seat. The seal can be effected by an annular graphite seal compressed between the trim assembly and the valve body, or by a metal-to-metal contact between the retention ring and the valve body.

대표청구항 ▼

What is claimed: 1. A fluid flow control device, comprising: a valve body defining an inlet, an outlet, and a throat disposed between the inlet and the outlet; a control element disposed within the throat of the valve body and adapted for displacement between a first position and a second position

What is claimed: 1. A fluid flow control device, comprising: a valve body defining an inlet, an outlet, and a throat disposed between the inlet and the outlet; a control element disposed within the throat of the valve body and adapted for displacement between a first position and a second position for controlling the flow of fluid through the valve body; a trim assembly comprising a valve seat and a retention ring, the valve seat fixed to the valve body within the throat, the retention ring threadably connected to the valve seat; and a seal comprising a graphite material, the seal compressed between the valve seat and the retention ring and engaging the valve body to provide a fluid tight seal between the trim assembly and the valve body wherein the valve seat comprises a seat ring portion and an upper ring portion disposed opposite the throat from the seat ring portion, the seat ring portion threadably connected to the valve body and defining a first seating surface adapted to be engaged by the control element when the control element is in the first position, the upper ring portion threadably connected to the retention ring wherein the retention ring defines a second seating surface adapted to be engaged by the control element when the control element is in the second position. 2. The device of claim 1, wherein the seal is constructed to withstand a temperature of at least 450° F. (232.22° C.). 3. The device of claim 1, wherein the seal further comprises a non-metallic, inorganic, passivating inhibitor for corrosion and oxidation resistance. 4. The device of claim 1, wherein the seal comprises a density in the range of approximately 85 lb/ft3 (1362 kg/m3) to approximately 95 lb/ft3 (1522 kg/m3). 5. The device of claim 1, wherein the seal comprises at least 90% graphite. 6. The device of claim 1, wherein the seal comprises a wound graphite ribbon. 7. The device of claim 1, wherein the seal comprises alternating layers of flexible graphite sheets and polytetrafluoroethylene sheets. 8. The device of claim 1, wherein the upper ring portion of the valve seat comprises an annular recess accommodating the seal at a location between the trim assembly and the valve body. 9. The device of claim 1, wherein the retention ring comprises an annular recess accommodating the seal at a location between the trim assembly and the valve body. 10. The device of claim 1, wherein the retention ring defines an inner cylindrical surface adapted to guide the control element between the first and second positions. 11. The device of claim 10, further comprising a piston ring comprising a graphite material, the piston ring disposed between the inner cylindrical surface of the retention ring and the control element to provide a fluid tight seal between the trim assembly and the control element. 12. The device of claim 11 wherein the retention ring defines an annular recess adjacent to the inner cylindrical surface, the annular recess accommodating the piston ring. 13. A fluid flow control device, comprising: a valve body defining an inlet, an outlet, and a throat disposed between the inlet and the outlet; a control element disposed within the throat of the valve body and adapted for displacement between a first position and a second position for controlling the flow of fluid through the valve body; a valve seat fixed against axial displacement relative to the valve body, the valve seat comprising a seat ring portion and an upper ring portion disposed opposite the throat from the seat ring portion, the seat ring portion defining a first seating surface adapted to be engaged by the control element when the control element is in the first position; a retention ring threadably connected to the upper ring portion of the valve seat, the retention ring defining a second seating surface adapted to be engaged by the control element when the control element is in the second position; an annular recess formed in at least one of the upper ring portion of the valve seat and the retention ring, the annular recess disposed adjacent to the valve body; and a seal comprising a graphite material, the seal disposed within the annular recess and in engagement with the valve body to provide a fluid tight seal between the annular recess and the valve body. 14. The device of claim 13 wherein the seal is compressed between the retention ring and the upper ring portion of the valve seat. 15. The device of claim 13 wherein the seal is constructed to withstand a temperature of at least 450° F. (232.22° C.). 16. The device of claim 13, wherein the seal further comprises a non-metallic, inorganic, passivating inhibitor for corrosion and oxidation resistance. 17. The device of claim 13, wherein the seal comprises a density in the range of approximately 85 lb/ft3 (1362 kg/m3) to approximately 95 lb/ft3 (1522 kg/m3). 18. The device of claim 13, wherein the seal comprises at least 90% graphite. 19. The device of claim 13, wherein the seal comprises a wound graphite ribbon. 20. The device of claim 13, wherein the seal comprises alternating layers of flexible graphite sheets and polytetrafluoroethylene sheets. 21. The device of claim 13, wherein the seat ring portion of the valve seat is threadably connected to the valve body. 22. The device of claim 13, wherein the control element comprises an unbalanced valve plug and the retention ring defines a second seating surface adapted to be engaged by the control element when the control element is in the second position. 23. The device of claim 13, wherein the control element comprises a balanced valve plug and the retention ring defines an inner cylindrical surface adapted to guide the control element between the first and second positions. 24. The device of claim 23, further comprising a piston ring disposed within an annular recess formed adjacent the inner cylindrical surface of the retention ring and the control element for providing a fluid tight seal between the trim assembly and the control element, the piston ring comprising a graphite material. 25. A trim assembly adapted to be installed within a fluid flow control device comprising a valve body and a control element, the valve body defining an inlet, an outlet, and a throat disposed between the inlet and the outlet, the control element disposed within the throat and adapted to be displaced between a first position and a second position for controlling the flow of fluid through the valve body, the trim assembly comprising: a valve seat adapted to be threadably connected to the valve body adjacent to the throat, the valve seat comprising a seat ring portion and an upper ring portion, the seat ring portion defining a first seating surface adapted to be engaged by the control element when the control element is in the first position, the upper ring portion defining an outer cylindrical surface and an inner cylindrical surface and adapted to be disposed opposite the throat from the seat ring portion; a retention ring threadably connected to the upper ring portion of the valve seat and defining an outer cylindrical surface; an annular recess formed in the outer cylindrical surface of one of the upper ring portion of the valve seat and the retention ring; and a seal comprising a graphite material disposed within the annular recess and adapted to be compressed between the retention ring and the upper ring portion of the valve seat wherein the retention ring defines a second seating surface adapted to be engaged by the control element when the control element is in the second position. 26. The device of claim 25, wherein the seal is constructed to withstand a temperature of at least 450° F. (232.22° C.). 27. The device of claim 25, wherein the graphite material of the seal comprises a non-metallic, inorganic, passivating inhibitor for corrosion and oxidation resistance. 28. The device of claim 25, wherein the seal comprises a density in the range of approximately 85 lb/ft3 (1362 kg/m3) to approximately 95 lb/ft3 (1522 kg/m3). 29. The device of claim 25, wherein the seal comprises at least 90% graphite. 30. The device of claim 25, wherein the seal comprises a wound graphite ribbon. 31. The device of claim 25, wherein the seal comprises alternating layers of flexible graphite sheets and polytetrafluoroethylene sheets. 32. The device of claim 25, further comprising a piston ring comprising a graphite material, the piston ring disposed within an annular recess formed adjacent to the inner cylindrical surface of the retention ring and the control element to provide a fluid tight seal between the trim assembly and the control element. 33. A fluid flow control device, comprising: a valve body defining an inlet, an outlet, and a throat disposed between the inlet and the outlet; a control element disposed within the throat of the valve body and adapted for displacement between a first position and a second position for controlling the flow of fluid through the valve body; a trim assembly comprising: a valve seat fixed against axial displacement relative to the valve body, the valve seat comprising a seat ring portion and an upper ring portion disposed opposite the throat from the seat ring portion, the seat ring portion defining a first seating surface adapted to be engaged by the control element when the control element is in the first position, and a retention ring threadably connected to the upper ring portion of the valve seat, the retention ring defining a second seating surface adapted to be engaged by the control element when the control element is in the second position; and a fluid tight seal defined at an interface between the trim assembly and the valve body at a location adjacent to the retention ring, the fluid tight seal provided by at least one of the following: an annular seal comprising a graphite material that is compressed between the retention ring and the upper ring portion of the valve seat, the annular seal sealingly engaging the valve body, and a metal-to-metal contact between an external surface of the retention ring and the valve body. 34. The device of claim 33, wherein the fluid-tight seal can withstand a temperature of at least 450° F. (232.22° C.). 35. The device of claim 33, wherein the annular seal comprises at least 90% graphite. 36. The device of claim 33, wherein the annular seal comprises a wound graphite ribbon. 37. The device of claim 33, wherein the annular seal comprises alternating layers of flexible graphite sheets and polytetrafluoroethylene sheets. 38. The device of claim 33, wherein one of the upper ring portion of the valve seat and the retention ring comprises an annular recess accommodating the annular seal at a location between the trim assembly and the valve body. 39. The device of claim 33, wherein the retention ring comprises a stepped side profile defining a shoulder surface in line contact with the upper web of the valve body.