Fluid end for positive displacement pump systems

Abstract

Aspects of the disclosure generally relate to positive displacement pumps, and more specifically to fluid end designs for plunger pumps typically used to stimulate oil and natural gas wells underground shale formations by means of hydraulic fracturing (also referred to as fracing or fracking). The fluid end designs include an intersection-less fluid end having an inline discharge and suction valve assembly. The fluid end designs an in-line suction and discharge valve assembly.

1 . A pump system, comprising:
 a fluid end body;   a suction valve member disposed in the fluid end body and movable between an open and a closed position;   a discharge valve member disposed in the fluid end body and movable between an open and a closed position; and   a valve seat disposed in the fluid end body, wherein the discharge valve member seals against the valve seat when in the closed position, and wherein the suction valve member seals against the discharge valve member when in the closed position.   
     
     
         2 . The pump system of  claim 1 , further comprising:
 a first valve guide and a second valve guide supporting the suction valve member;   a suction valve biasing member biasing the suction valve member into contact with the discharge valve member; and   a discharge valve biasing member biasing the discharge valve member into contact with the valve seat.   
     
     
         3 . The pump system of  claim 2 , wherein the suction valve biasing member forces the suction valve member in a first direction, wherein the discharge valve biasing member forces the discharge valve member in a second, opposite direction, and wherein a central axis of the suction valve member is aligned with a central axis of the discharge valve member. 
     
     
         4 . The pump system of  claim 2 , wherein the discharge valve biasing member is disposed between the discharge valve member and a cover seal that is disposed within the fluid end body. 
     
     
         5 . The pump system of  claim 2 , further comprising:
 a spring retainer, wherein the suction valve biasing member is disposed between the second valve guide and the spring retainer; and   a locking device, wherein one end of the locking device is coupled to the suction valve member, and wherein an opposite end of the locking device is coupled to the spring retainer to secure the suction valve biasing member between the second valve guide and the spring retainer.   
     
     
         6 . The pump system of  claim 5 , wherein the locking device comprises one or more locking members that extend outward into engagement with the suction valve member to couple the locking device to the suction valve member. 
     
     
         7 . The pump system of  claim 6 , wherein the locking device comprises a release button that allows the locking members to retract inward to de-couple the locking device from the suction valve member. 
     
     
         8 . The pump system of  claim 1 , wherein the suction valve member is movable with the discharge valve member when the discharge valve member moves from the closed position to the open position. 
     
     
         9 . The pump system of  claim 1 , further comprising:
 a connection housing coupled to the fluid end body; and   a cylinder housing at least partially disposed within and between the connection housing and the fluid end body, wherein the valve seat is coupled to the cylinder housing.   
     
     
         10 . The pump system of  claim 9 , further comprising a plunger that extends into a chamber of the cylinder housing, wherein during a suction stroke of the plunger, pressurized fluid flows from an inlet of the fluid end body into the chamber, and wherein during a discharge stroke of the plunger, the pressurized fluid flows from the chamber into an outlet of the fluid end body. 
     
     
         11 . The pump system of  claim 10 , wherein during the suction stroke, the suction valve member moves from the closed position to the open position and out of contact with the discharge valve. 
     
     
         12 . The pump system of  claim 11 , wherein during the discharge stroke, the suction valve member remains in contact with the discharge valve member as the discharge valve member moves from the closed to the open position and out of contact with the valve seat. 
     
     
         13 . The pump system of  claim 12 , further comprising a cover seal and a cover nut configured to secure the suction valve member and the discharge valve member within the fluid end body. 
     
     
         14 . The pump system of  claim 13 , wherein the cover nut is threaded into the fluid end body against the cover seal, and wherein the cover seal is coupled to a seal member that seals between an outer surface of the discharge valve member and an inner surface of the fluid end body. 
     
     
         15 . The pump system of  claim 1 , further comprising a measurement device configured to measure a position of the suction and discharge valve members within the fluid end body. 
     
     
         16 . A method of operating a pump system, comprising:
 pumping pressurized fluid from one or more inlets of a fluid end body into a chamber of a cylinder housing, wherein the pressurized fluid forces a suction valve member into an open position to allow fluid flow into the chamber; and   pumping the pressurized fluid from the displacement chamber into one or more outlets of the fluid end body, wherein the pressurized fluid forces a discharge valve member into an open position to allow fluid flow out of the chamber, wherein the suction valve member remains in contact with the discharge valve member when the discharge valve member is moved into the open position.   
     
     
         17 . The method of  claim 16 , further comprising biasing the suction valve member into a closed position against the discharge valve member via a suction valve biasing member, and biasing the discharge valve member into a closed position against a valve seat via a discharge valve biasing member, wherein a central axis of the suction valve member is aligned with a central axis of the discharge valve member. 
     
     
         18 . The method of  claim 17 , further comprising securing the suction valve biasing member between a valve guide and a spring retainer via a locking device, wherein the locking device is coupled to the spring retainer and the suction valve member to secure the suction valve biasing member between the valve guide and the spring retainer. 
     
     
         19 . The method of  claim 17 , further comprising securing the discharge valve biasing member between the discharge valve member and a cover seal disposed within the fluid end body. 
     
     
         20 . The method of  claim 19 , further comprising measuring a position of the suction and discharge valve members within the fluid end body.