Seal assembly for a fluid pressure control device

Abstract

A seal assembly for a fluid pressure control device includes a guide element having a sealing surface and a first guide surface. A throttling element assembly includes a throttling element positionable within a fluid flow path, the assembly defining a mating surface adapted to seal with the guide element sealing surface and a second guide surface sized to slidingly engage the first guide surface of the guide element. A relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces to receive loose solid material, thereby to prevent disruption of the seal formed between the sealing surface and the mating surface.

1 . A fluid pressure control device comprising: 
 a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet;    a guide element coupled to the body and defining a sealing surface and a first guide surface; and    a plug assembly including a plug positionable within the flow path and coupled to a stem, the plug assembly defining a mating surface adapted to seal with the guide element sealing surface and a second guide surface sized to slidingly engage the first guide surface of the guide element;    wherein a relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces.    
   
   
       2 . The fluid pressure control device of  claim 1 , in which the relief void is formed as a groove having a volume sufficient to receive material removed from a surface of at least one of the plug assembly and the guide element.  
   
   
       3 . The fluid pressure control device of  claim 1 , in which the guide element comprises a seat defining the sealing surface and the first guide surface, and in which the plug defines the mating surface and the second guide surface, wherein the plug mating surface sealingly engages the seat sealing surface when the plug is in a closed position.  
   
   
       4 . The fluid pressure control device of  claim 3 , in which the relief is further positioned adjacent the seat sealing surface and plug mating surface.  
   
   
       5 . The fluid pressure control device of  claim 1 , in which the guide element comprises a cage having an interior surface defining the sealing surface and the first guide surface.  
   
   
       6 . The fluid pressure control device of  claim 5 , in which the plug assembly includes a guide ring sized to slidingly engage the cage interior surface, thereby to define the second guide surface, and a seal ring having an exterior surface sized to slidingly engage and seal with the cage interior surface, thereby to define the mating surface.  
   
   
       7 . The fluid pressure control device of  claim 6 , in which a first recessed portion of the plug forms the relief void.  
   
   
       8 . The fluid pressure control device of  claim 7 , in which the first recessed portion of the plug is positioned adjacent the seal ring.  
   
   
       9 . The fluid pressure control device of  claim 7 , in which the first recessed portion of the plug is positioned between the guide ring and the seal ring.  
   
   
       10 . The fluid pressure control device of  claim 8 , further comprising a second relief void formed by a second recessed portion of the plug formed on a side of the seal ring opposite the first recessed portion of the plug.  
   
   
       11 . The fluid pressure control device of  claim 1 , in which the guide element comprises a packing assembly defining the sealing surface and the first guide surface, and in which the stem has an exterior surface defining the mating surface and the second guide surface.  
   
   
       12 . The fluid pressure control device of  claim 11 , in which the sealing surface and first guide surface are defined by a same interior surface of the packing assembly and in which the mating surface and second guide surface are defined by a same portion of the stem exterior surface.  
   
   
       13 . A seal assembly for a fluid pressure control device having a body defining an inlet, an outlet, and a fluid flow path extending from the inlet to the outlet, the seal assembly comprising: 
 a guide element coupled to the body and defining a sealing surface and a first guide surface; and    a throttling element assembly including a throttling element positionable within the flow path, the throttling element assembly defining a mating surface adapted to seal with the guide element sealing surface and a second guide surface sized to slidingly engage the first guide surface of the guide element;    wherein a relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces.    
   
   
       14 . The seal assembly of  claim 13 , in which the relief void is formed as a groove having a volume sufficient to receive material removed from a surface of at least one of the throttling element assembly and the guide element.  
   
   
       15 . The seal assembly of  claim 13 , in which the guide element comprises a seat defining the sealing surface and the first guide surface, and in which the throttling element comprises a plug defining the mating surface and the second guide surface, wherein the plug mating surface sealingly engages the seat sealing surface when the plug is in a closed position.  
   
   
       16 . The seal assembly of  claim 15 , in which the relief is further positioned adjacent the seat sealing surface and plug mating surface.  
   
   
       17 . The seal assembly of  claim 13 , in which the guide element comprises a cage having an interior surface defining the sealing surface and the first guide surface, and in which the throttling element comprises a plug assembly defining the mating surface and the second guide surface.  
   
   
       18 . The seal assembly of  claim 17 , in which the plug assembly includes a guide ring sized to slidingly engage the cage interior surface, thereby to define the second guide surface, and a seal ring having an exterior surface sized to slidingly engage and seal with the cage interior surface, thereby to define the mating surface.  
   
   
       19 . The seal assembly of  claim 18 , in which a first recessed portion of the plug forms the relief void.  
   
   
       20 . The seal assembly of  claim 19 , in which the first recessed portion of the plug is positioned adjacent the seal ring.  
   
   
       21 . The seal assembly of  claim 19 , in which the first recessed portion of the plug is positioned between the guide ring and the seal ring.  
   
   
       22 . The seal assembly of  claim 20 , further comprising a second relief void formed by a second recessed portion of the plug formed on a side of the seal ring opposite the first recessed portion of the plug.  
   
   
       23 . The seal assembly of  claim 13 , in which the guide element comprises a packing assembly defining the sealing surface and the first guide surface, and in which the throttling element assembly comprises a stem coupled to the throttling element and having an exterior surface defining the mating surface and the second guide surface.  
   
   
       24 . The seal assembly of  claim 23 , in which the sealing surface and first guide surface are defined by a same interior surface of the packing assembly and in which the mating surface and second guide surface are defined by a same portion of the stem exterior surface.