Multi-piece seat

Abstract

A multi-piece seat having a base and a top. Some embodiments may have a seal. The multi-piece seat is configured to be installed in a conventional fluid end. Installation of the multi-piece seat is simplified by the separate components. The base may be installed easily without an interference fit. The top may be installed easily with an interference fit but with a smaller engagement area than the prior art. Removal and replacement of any of the components is simplified for the same reasons. Operating cost is reduced by only using the harder material in the component that engages the valve. Additional components may be added to increase the height of the seal assembly.

Claims: 
     
         1 . An apparatus, comprising:
 a valve seat configured to seal against a valve body, the valve seat comprising:
 a base, comprising:
 a first surface; 
 a second surface opposed to the first surface; 
 a base outer surface interconnecting the first and second surfaces; and 
 a base bore extending through the first and second surfaces; 
 
 a top, comprising:
 a top surface; 
 a bottom surface opposed to the top surface; 
 a top outer surface interconnecting the top and bottom surfaces; and 
 a top bore extending through the top and bottom surfaces; and 
 
 a seal installed in the top outer surface. 
   
     
     
         2 . The apparatus of  claim 1 , in which the base is formed from a first material and the top is formed from a second material. 
     
     
         3 . The apparatus of  claim 2 , in which the second material is harder than the first material. 
     
     
         4 . The apparatus of  claim 1 , in which the base and top abut one another but do not interlock. 
     
     
         5 . The apparatus of  claim 1 , in which the first surface of the base abuts the bottom surface of the top. 
     
     
         6 . The apparatus of  claim 1 , in which the top bore comprises a tapered sealing surface configured to engage a tapered valve body surface of the valve body. 
     
     
         7 . The apparatus of  claim 1 , in which the top outer surface comprises a top taper having a seal groove, the seal groove configured to receive the seal. 
     
     
         8 . The apparatus of  claim 7 , in which the seal groove is annular and comprises first and second side walls connected by a base. 
     
     
         9 . The apparatus of  claim 8 , in which the first and second side walls transition smoothly to the base via radiused wall portions. 
     
     
         10 . The apparatus of  claim 7 , in which a cross-section of the seal groove is semi-circle shaped. 
     
     
         11 . The apparatus of  claim 1 , in which the base bore is concentric with the top bore. 
     
     
         12 . The apparatus of  claim 1 , in which the base bore and the top bore have the same inner diameters. 
     
     
         13 . A fluid end, comprising:
 a fluid end body having a fluid passage bore formed therein; and   the apparatus of  claim 1  installed within the fluid passage bore.   
     
     
         14 . The fluid end of  claim 13 , in which the top is installed via an interference fit within the fluid passage bore. 
     
     
         15 . A method of assembling the fluid end of  claim 13 , the method comprising:
 inserting the base in the fluid passage bore of the fluid end body;   installing the seal within the top outer surface; and   inserting the top into the fluid passage bore such that the bottom surface of the top engages the first surface of the base.   
     
     
         16 . The apparatus of  claim 1 , in which the base outer surface comprises a straight section, a tapered section, and a transition radius connecting the straight and tapered sections. 
     
     
         17 . The apparatus of  claim 1 , in which the valve seat is configured to be installed within a fluid passage bore of a fluid end body; in which the base is not interference fit within the fluid passage bore. 
     
     
         18 . The apparatus of  claim 1 , in which the top outer surface is angled from a longitudinal axis of the top by an angle of 1.79 degrees. 
     
     
         19 . The apparatus of  claim 1 , in which the top comprises a body having a frusto-conical shape. 
     
     
         20 . The apparatus of  claim 1 , in which the first surface of the base comprises a groove, the apparatus further comprising:
 a face seal situated within the groove, the face seal configured to engage the bottom surface of the top;   in which the face seal is configured to prevent fluid from flowing between the first surface of the base and the bottom surface of the top.   
     
     
         21 . An apparatus, comprising:
 a valve seat configured to seal against a valve body, the valve seat comprising:
 a base, comprising:
 a first surface; 
 a second surface opposed to the first surface; 
 a base outer surface interconnecting the first and second surfaces; and 
 a base bore extending through the first and second surfaces; and 
 
 a top, comprising:
 a top surface; 
 a bottom surface opposed to the top surface; 
 a top outer surface interconnecting the top and bottom surfaces; and 
 a top bore extending through the top and bottom surfaces; 
 
 in which the base and top engage one another but do not interlock.