Multi-Piece Fluid End

Abstract

A fluid end is formed from a first body attached to a separate second body. Each body includes an external surface. When the bodies are attached, their respective external surfaces are in flush engagement. A plurality of bores are formed in the second body that are alignable with a plurality of corresponding bores formed in the first body. The fluid end may be used with seals disposed within recesses within each bore to seal against corresponding sealing surfaces. Further, retaining closures may be bolted to the fluid end bodies, such that the closures have a threadless connection to the fluid end bodies. Various combinations of such components may be utilized.

1 . A method, comprising:
 machining a plurality of bore pairs into a first block of steel having an external surface, in which each bore pair comprises:
 a first bore that extends through the first block and terminates at a first opening formed in the external surface; and 
 a second bore that extends through the first block, intersects the first bore, and terminates at a second opening formed in the external surface; and 
   machining a plurality of third bores into the second, different block of steel having an external surface, in which each third bore extends through the second block and terminates at a third opening formed in the external surface of the second block, each third opening alignable with a corresponding second opening formed in the external surface of the first block to create a fluid end.   
     
     
         2 . A method, comprising:
 dividing a single block of material parallel to its length into multiple blocks;   machining the multiple blocks into corresponding first fluid end bodies; and   mating respective ones of the first fluid end bodies with corresponding second fluid end bodies to yield multiple fluid end assemblies.   
     
     
         3 . The method of  claim 2  in which the second fluid end bodies are machined from a different material than the first fluid end bodies. 
     
     
         4 . The method of  claim 2  in which the first fluid end bodies are formed from stainless steel. 
     
     
         5 . The method of  claim 2  in which the second fluid end bodies are formed from cast iron. 
     
     
         6 . The method of  claim 2  further comprising machining at least one of the multiple blocks into at least one of the corresponding second fluid end bodies. 
     
     
         7 . The method of  claim 2  further comprising:
 machining at least one plunger bore in each of the first fluid end bodies; and 
 aligning the at least one plunger bore with at least one corresponding bore in the corresponding second fluid end bodies. 
 
     
     
         8 . The method of  claim 2  in which the multiple fluid end assemblies are flangeless. 
     
     
         9 . A fluid end kit comprising:
 a first fluid end body that includes:
 an external surface having a front side and an opposed back side; and 
 a plurality of bore pairs, each bore pair comprising:
 a first bore extending through the first fluid end body and terminating at an opening formed in the external surface; and 
 a second bore extending through the first fluid end body, intersecting the first bore, and terminating at an opening formed in the external surface; and 
 
   a plurality of second fluid end body pieces distinct from one another and from the first fluid end body, each having a front side and an opposed back side, in which the plurality of second fluid end body pieces are positionable to engage with the back side of the first fluid end body to form a flangeless fluid end assembly having a plurality of bores, each of which extends through a respective one of the second fluid end body pieces, each bore terminating at an opening formed in the external surface of its respective second fluid end body piece, and each opening alignable with a corresponding opening formed in the external surface of the first fluid end.