Seal for a fluid assembly

Abstract

A fluid assembly comprising a first part ( 28 ) and a second part ( 30 ) which interact by relative linear movement therebetween. A groove ( 40 ) extends around the circumference of the cylindrical interacting surface ( 36 ) of the first part ( 38 ) and a seal ( 50 ) is situated within the groove ( 40 ). The seal ( 50 ) has a radial face ( 64 ) which converts from a concave profile to a flat profile flush with the groove's root side ( 54 ) upon interface with the interacting surface ( 38 ) of the second part ( 30 ). The seal ( 50 ) also has axial faces ( 62 ) which each assume a more pronounced concave profile upon such interfacing, the concave profiles forming cavities ( 68 ) which, when filled with fluid, urge the radial seal face ( 64 ) and radial seal face ( 66 ) towards the groove's root side ( 54 ) and the interacting surface ( 38 ) of the second part ( 30 ).

1 . A fluid assembly comprising a first part, a second part, and a seal positioned within a groove in the first part; 
 the first part having a cylindrical interacting surface and the second part having a cylindrical interacting surface, one of these interfacing surfaces being a radially inner surface of the part and the other of these interacting surfaces being a radially outer surface of the part;    the first part and the second part interacting by relative linear movement therebetween, the respective interacting surfaces and the interacting surfaces interfacing with each other during such interaction;    the groove extending around the circumference of the interacting surface of the first part, the groove having two axial sides extending radially outward/inward from the interacting surface, and a root side spanning terminating edges of the axial sides;    the seal comprising two axial faces, a root-adjacent radial face, and an interface-adjacent radial face;    the seal having a pre-installation shape prior to installation into the groove, an installed pre-interfacing shape when installed in the groove but prior to the second part interfacing with the first part, and an interfacing shape when the second part interfaces with the first part;    the root-adjacent radial face having a radially concave profile when the seal is in its pre-installation shape and a flat profile flush against the groove root side when the seal is in its interfacing shape, the flat profile applying surface contact pressure against the groove root side; and    the axial faces each having a radially concave profile when the seal is in its pre-installation shape and a more pronounced radially concave profile when the seal is in its interfacing shape; the more pronounced radially convex profiles forming cavities which, when filled with fluid, urge the root-adjacent seal face towards the groove root side and urge the interface-adjacent seal face towards the interfacing surface of the second part.    
   
   
       2 . A fluid assembly as set forth in  claim 1 , wherein the cylindrical interacting surface of the first part is the radially inner surface and the groove extend radially outward therefrom.  
   
   
       3 . A fluid assembly as set forth in  claim 1 , wherein the cylindrical interfacing surface of the first part is the radially outer surface and the groove extends radially inward therefrom.  
   
   
       4 . A fluid assembly as set forth in  claim 1 , wherein root-adjacent regions of the seal axial faces of the seal apply surface contact pressure against root-adjacent regions of the groove axial sides.  
   
   
       5 . A fluid assembly as set forth in  claim 1 , wherein the concave profile of the root-adjacent radial face, when the seal is the relaxed pre-installation condition, is symmetrical relative to seal circumference.  
   
   
       6 . A fluid assembly as set forth in  claim 1 , wherein the concave profiles of the axial seal faces are symmetrical relative to the seal circumference.  
   
   
       7 . A fluid assembly as set forth in  claim 1 , wherein root-adjacent regions of the seal axial faces are axially compressed when the seal is in its installed pre-interfacing condition.  
   
   
       8 . A fluid assembly as set forth in  claim 1 , wherein the seal further comprises a hard heel.  
   
   
       9 . A fluid assembly as set forth in  claim 1 , wherein the seal further comprises an internal expander.  
   
   
       10 . A fluid assembly as set forth in  claim 1 , wherein the seal is made from an elastomeric polymeric material.  
   
   
       11 . A fluid assembly as set forth in  claim 10 , wherein the elastomeric polymeric material is selected from the group consisting of filled or unfilled natural rubbers, synthetic rubbers, and fluoropolymers.  
   
   
       12 . A fluid assembly as set forth in  claim 1 , wherein the first part comprises a first conduit having a female coupling member and the second part comprises a second conduit having a male coupling member, the conduits forming a fluid line when coupled together, and wherein the interfacing surface of the first part in a radially inner surface of the female coupling member and the groove extends radially outward therefrom.  
   
   
       13 . A fluid assembly as set forth in  claim 12 , wherein the fluid line is a choke line or a kill line in an offshore drilling system.  
   
   
       14 . A fluid assembly as set forth in  claim 1 , wherein the first part comprises a cylinder head having a central bore and the second part comprises a rod extending through the central bore, and wherein the interfacing surface of the first part is the radially inner surface forming the central bore and the groove extends radially outward therefrom.  
   
   
       15 . A fluid assembly as set forth in  claim 1 , wherein the first part comprises a piston and the second part comprises a cylinder and wherein the interfacing surface of the first part is the radially outer surface of the piston and the groove extends radially inward therefrom.