Fluid end with removable dual-valve cartridge

Abstract

A fluid end assembly is described herein with a flow box having an inlet manifold having an inlet opening, an outlet manifold having an outlet opening, and a housing between the inlet manifold and the outlet manifold; and a valve cartridge removably disposed in the housing. In one embodiment, the valve cartridge includes a sleeve with a first end and a second end; a valve seat at each of the first and second ends; a first valve disposed in the sleeve at the first end; and a second valve disposed in the sleeve at the second end.

What is claimed is: 
     
         1 . A fluid end assembly, comprising:
 a flow box with an inlet manifold having an inlet opening, an outlet manifold having an outlet opening, and a housing between the inlet manifold and the outlet manifold; and   a valve cartridge removably disposed in the housing, the valve cartridge comprising:
 a first valve seat at a first end of the cartridge assembly and a second valve seat spaced apart from the first end; 
 a first valve disposed in the cartridge assembly at the first end; 
 a second valve disposed adjacent to the second valve seat; 
 a first resilient member disposed between the first and second valves in contact with the first valve and the second valve; and 
 a second resilient member disposed between the second valve and a second end of the cartridge assembly opposite the first end. 
   
     
     
         2 . The fluid end assembly of  claim 1 , wherein each valve seat engages with a sleeve disposed in the housing. 
     
     
         3 . The fluid end assembly of  claim 2 , wherein the sleeve has a first lip extending radially inward at a first end of the sleeve, the first valve seat has a lip that extends radially outward, and the lip of the first valve seat engages the first lip. 
     
     
         4 . The fluid end of  claim 3 , wherein the sleeve has a second end opposite from the first end, the second valve seat has a lip that extends radially outward, and the lip of the second valve seat engages with the second end of the sleeve. 
     
     
         5 . The fluid end of  claim 1 , wherein the first valve seat is connected to the second valve seat by a plurality of posts. 
     
     
         6 . The fluid end of  claim 5 , wherein each of the first and second valves has a stem, the stem of the second valve is hollow, and the stem of the first valve is disposed within the stem of the second valve. 
     
     
         7 . The fluid end of  claim 6 , wherein the first resilient member is disposed within the stem of the second valve. 
     
     
         8 . The fluid end of  claim 1 , wherein the first valve has a first stem, the second valve has a second stem that is hollow, the first stem fits within the second stem, and the first resilient member is disposed within the second stem. 
     
     
         9 . A valve cartridge, comprising:
 a cage comprising a first valve seat and a second valve seat;   a first valve disposed in the cage, the first valve having a first stem and a first plug portion;   a second valve disposed in the cage, the second valve having a second stem and a second plug portion, wherein the second stem is hollow and the first stem fits within the second stem;   a first resilient member disposed within the second stem between the first stem and the second plug portion; and   a second resilient member disposed between the second plug portion and the cage, wherein the second valve seat is between the first plug portion and the second plug portion.   
     
     
         10 . The valve cartridge of  claim 9 , wherein the first valve seat and the second valve seat are connected by a plurality of posts. 
     
     
         11 . The valve cartridge of  claim 10 , wherein the cage further comprises a top plate with an alignment bore, and the second valve has a rear stem that fits within the alignment bore. 
     
     
         12 . The valve cartridge of  claim 11 , wherein the second resilient member contacts the second plug portion and the top plate. 
     
     
         13 . The valve cartridge of  claim 12 , further comprising a first groove along a bottom surface of the cage and a second groove around a periphery of the second valve seat. 
     
     
         14 . The valve cartridge of  claim 13 , wherein the second valve seat is connected to the top plate by a plurality of posts. 
     
     
         15 . A valve cartridge, comprising:
 a first valve aligned with a second valve;   a first valve seat at a first end of the valve cartridge adjacent to the first valve;   a second valve seat between the first valve and the second valve; and   a resilient member between the first valve and the second valve in contact with the first valve and the second valve.   
     
     
         16 . The valve cartridge of  claim 15 , further comprising a second resilient member between the second valve and a second end of the valve cartridge opposite from the first end. 
     
     
         17 . The valve cartridge of  claim 16 , wherein the first valve has a first stem, the second valve has a second stem that is hollow, and the first stem fits within the second stem.