Isolation gap in fluid end dynamic body

Abstract

A dynamic section of a fluid end. The dynamic section has a through-bore which is surrounded by an isolation ring of constant thickness. The isolation ring is separated from the remainder of the dynamic section body by an isolation gap, which is a groove cut into the dynamic section body. The use of such an isolation ring prevents transmission of, and reception of, uneven forces which might tend to stress or damage wear elements and seals disposed within the through-bore. The isolation ring may be used on each side of the through-bore at the surface, and the isolation gap separating the isolation ring from the rest of the dynamic section may be deeper than the section of the through-bore containing the wear rings and seals.

1 . A fluid end, comprising:
 a dynamic body having a first end and a second end, wherein the dynamic body has at least one internal through-bore extending about a central, longitudinal axis from a first opening at the first end to a second opening at the second end, the dynamic body comprising a first circumferential isolation ring formed at the first end of the dynamic body about the first opening and is concentric about the central, longitudinal axis of the at least one internal through-bore; and   a static body, attached to the dynamic body at the first end.   
     
     
         2 . The fluid end of  claim 1  in which the dynamic body further comprises a second circumferential isolation ring formed in the second end about the second opening, wherein the second circumferential isolation ring is concentric about the at least one internal through-bore. 
     
     
         3 . The fluid end of  claim 2  in which:
 a first isolation gap is formed about the first circumferential isolation ring; and 
 a second isolation gap is formed about the second circumferential isolation ring; 
 wherein each of the first isolation gap and the second isolation gap form a circumferential groove having a rectangular cross-section. 
 
     
     
         4 . The fluid end of  claim 1  further comprising at least one plunger, extending through the at least one internal through-bore of the dynamic body, the at least one plunger being configured to reciprocate along the central, longitudinal axis of the at least one through-bore. 
     
     
         5 . The fluid end of  claim 1  in which the at least one internal through-bore defines:
 a first enlarged section extending a first length proximate the first opening; 
 a second enlarged section extending a second length proximate the second opening; and 
 an intermediate section extending between the first enlarged section and the second enlarged section, the intermediate section having a circumference that is less than the first enlarged section and the second enlarged section. 
 
     
     
         6 . The fluid end of  claim 5  in which the first circumferential isolation ring is bounded on a first side by the first enlarged section and a second side by a circumferential isolation gap, in which the circumferential isolation gap has a depth greater than the first length. 
     
     
         7 . The fluid end of  claim 5  in which the dynamic body further comprises a second circumferential isolation ring formed in the second end about the second opening, wherein the second circumferential isolation ring is concentric about the at least one internal through-bore. 
     
     
         8 . The fluid end of  claim 7  in which:
 the first circumferential isolation ring is bounded on a first side by the first enlarged section and a second side by a first circumferential isolation gap, in which the first circumferential isolation gap has a depth greater than the first length; and 
 the second circumferential isolation ring is bounded on a first side by the second enlarged section and a second side by a circumferential isolation gap, in which the second circumferential isolation gap has a depth greater than the second length. 
 
     
     
         9 . The fluid end of  claim 8  in which each of the first circumferential isolation gap and the second circumferential isolation gap define a rectilinear cross-section. 
     
     
         10 . A fluid end, comprising:
 a static body having five bores;   a dynamic body having a first surface and a second surface, in which the dynamic body is attached to the static body at the first surface, and wherein the dynamic body has five through-bores extending from the first surface to the second surface, in which the dynamic body is attached to the static body such that each of the five through-bores is aligned with a selected one of the five bores of the static body about a central axis; and wherein each of the five through-bores defines:
 a first section at a first end of the through-bore, concentric about the central axis; 
 a second section at a second end of the through-bore, concentric about the central axis; and 
 an intermediate section disposed between the first section and the second section and concentric about the central axis, in which the intermediate section meets the first section at a first annular shoulder and the second section at a second annular shoulder; and wherein:
 the first section is circumscribed by a first isolation ring formed in the first surface of the dynamic body, wherein the first isolation ring is bounded on an inside surface by the through-bore and on an outside surface by a first annular isolation gap formed in the first surface. 
 
   
     
     
         11 . The fluid end of  claim 10  in which the first annular isolation gap is defined by an inside annular wall, an outside annular wall, and a base, wherein the base is further from the first surface than the first annular shoulder. 
     
     
         12 . The fluid end of  claim 10  in which the intermediate section comprises a tapered section. 
     
     
         13 . The fluid end of  claim 10  wherein the second section is circumscribed by a second isolation ring formed in the second surface of the dynamic body, wherein the second isolation ring is bounded on an inside surface by the through-bore and on an outside surface by a second annular isolation gap formed in the second surface. 
     
     
         14 . The fluid end of  claim 10  in which the first annular isolation gap and the second annular isolation gap are each defined by an inside annular wall, an outside annular wall, and a base, wherein the base of the first annular isolation gap is further from the first surface than the first annular shoulder and the base of the second annular isolation gap is further from the second surface than the second annular shoulder. 
     
     
         15 . The fluid end of  claim 14  in which a first wear ring is installed within the first section of the through-bore, and wherein a second wear ring is installed within the second section of the through-bore. 
     
     
         16 . A pump, comprising:
 a power end having five plungers; and   the fluid end of claim  15 , wherein each of the five plungers are disposed within a selected one of the five through-bores of the dynamic section.   
     
     
         17 . A dynamic body section for use with a fluid end in a hydraulic fracturing pump, the dynamic body section comprising:
 a body having a first side and a second side and at least one through-bore interconnecting the first side and the second side, in which the at least one through-bore extends about a central axis;   a first isolation ring disposed on the first side of the dynamic body section, concentric about the central axis; and   a second isolation ring disposed on the second side of the dynamic body section, concentric about the central axis.   
     
     
         18 . The dynamic body section of  claim 17  in which the first isolation ring has a consistent width. 
     
     
         19 . The dynamic body section of  claim 17  further comprising:
 a first wear ring disposed in the through-bore at a position where the through-bore is circumscribed by the first isolation ring; and 
 a second wear ring disposed in the through-bore at a position where the through-bore is circumscribed by the second isolation ring. 
 
     
     
         20 . The dynamic body section of  claim 19  in which an outside wall of the first isolation ring terminates in a base, in which the base is positioned further from the first side of the body than the first wear ring.