Valve assembly method

Abstract

A method for installing a valve for use in oil and gas production or similar applications includes inserting seats and biasing members into a cavity of the valve and causing the seats to moving axially apart from each other, such that the biasing members are compressed and the flow barrier of the valve may be installed between the seats.

What is claimed is: 
     
         1 . A method of assembling a valve comprising:
 inserting into a cavity of a valve body two seats and two biasing members disposed between the valve body and the seats, such that the seats are separated by a first axial distance;   inserting into the cavity of the valve body a flow barrier with a first width greater than the first axial distance;   moving the seats axially apart from each other, such that the biasing members are compressed and the seats are separated by a second axial distance which is greater than or substantially equal to the width of the flow barrier; and   moving the flow barrier to a position between the seats, such that the biasing members exert an axial force causing the seats to engage the flow barrier.   
     
     
         2 . The method of  claim 1 , wherein the step of moving the seats axially apart from each other is performed using an installation tool comprising two rods, each rod comprising a radially extending arm configured to engage one of the seats. 
     
     
         3 . The method of  claim 1 , wherein the step of moving the seats axially apart from each other is performed using an installation tool comprising a rod connecting two radially extending arms, each arm configured to engage one of the seats. 
     
     
         4 . The method of  claim 1 , wherein:
 the flow barrier comprises:
 a lower axial face with a second width that is less than the first width and less than the first axial distance; and 
 a beveled surface; and 
   the step of moving the seats axially apart from each other is performed using the beveled surface of the flow barrier.   
     
     
         5 . The method of  claim 1 , wherein:
 the valve further comprises a guide member attached to a lower face of the flow barrier, said guide member comprising:
 a lower axial face with a second width that is less than the first width and less than the first axial distance; and 
 a beveled surface; and 
   the step of moving the seats axially apart from each other is performed using the beveled surface of the guide member.   
     
     
         6 . The method of  claim 1 , wherein:
 the seats comprise:
 upper axial faces separated by a second axial distance that is greater than the first width and greater than the first axial distance; and 
 a beveled surface; and 
   the step of moving the seats axially apart from each other is performed using the beveled surface.   
     
     
         7 . The method of  claim 1 , wherein:
 the valve further comprises:
 an outer sleeve that slidingly engages the flow barrier such that both the outer sleeve and the flow barrier are inserted into the cavity of the valve body; and 
 two compression members, each comprising a lower flange configured to engage one of the seats, a substantially planar member, and an upper flared portion; and 
   the step of moving the seats axially apart from each other is performed using engagement between the outer sleeve and the upper flared portions of the compression members.