Gate valve and method of repairing same

Abstract

A gate valve for controlling flow of a fluid therethrough is provided. The gate valve includes a valve body having an outer surface, a bore, a valve cavity, a first seat pocket, a second seat pocket, and first and second fluid ports extending from the outer surface to the first and second seat pockets, respectively. First and second seats are positioned respectively within the first and second seat pockets. The seats include circumferential fluid channels and one or more conduits in fluid communication with the fluid ports for permitting a repair fluid to be injected into the ports to the faces of the seats. A gate is slidably positioned within the valve cavity between the first seat and the second seat for controlling flow of a fluid through the valve. Sand shields are also provided at the rear of the seats to capture particulates and to bias the seats against the gate.

What is claimed is: 
     
         1 . A method of repairing scratches or erosion in a gate valve, the method comprising:
 obtaining a gate valve including:
 a valve body having a bore, an outer surface, an upper end structured to couple to a bonnet, a valve cavity, a first seat pocket, a second seat pocket, a first fluid port extending from the outer surface to the first seat pocket, and a second fluid port extending from the outer surface to the second seat pocket, 
 a first seat positioned within the first seat pocket, the first seat having a first seat face and at least one first conduit in fluid communication with the first fluid port and the first seat face, 
 a second seat positioned within the second seat pocket, the second seat having a second seat face and at least one second conduit in fluid communication with the second fluid port and the second seat face, and 
 a gate slidably positioned within the valve cavity between the first seat face of the first seat and the second seat face of the second seat, the gate configured to be selectively positioned into an open position for permitting flow of the fluid through the bore and a closed position for preventing flow of a fluid through the bore; and 
   injecting a repair fluid into the first fluid port to repair scratches or erosion at a first gate/seat boundary between the first seat face of the first seat and a first surface of the gate.   
     
     
         2 . The method of  claim 1 , further comprising: injecting the repair fluid into the second fluid port to repair scratches or erosion at a second gate/seat boundary between the second seat face of the second seat and a second surface of the gate. 
     
     
         3 . The method of  claim 1 , wherein the step of injecting the repair fluid includes injecting the repair fluid during a fracking operation. 
     
     
         4 . The method of  claim 1 , wherein the repair fluid is a stem pack grease. 
     
     
         5 . The method of  claim 1 , wherein the repair fluid contains Tetrafluoroethylene. 
     
     
         6 . A method of repairing scratches or erosion in a gate valve, the method comprising:
 obtaining a gate valve including:
 a valve body having a bore, an outer surface, an upper end structured to couple to a bonnet, a valve cavity, a first seat pocket, a second seat pocket, and a fluid port extending from the outer surface to at least one of the first and second seat pockets, 
 a first seat positioned within the first seat pocket, the first seat having a first seat face, 
 a second seat positioned within the second seat pocket, the second seat having a second seat face, and 
 a gate slidably positioned within the valve cavity between the first seat face of the first seat and the second seat face of the second seat, the gate being selectively positionable into an open position for permitting flow of a fluid through the bore and a closed position for preventing flow of the fluid through the bore; and 
   injecting a repair fluid into the fluid port to repair scratches or erosion on at least one of the first seat face and the second seat face.   
     
     
         7 . The method of  claim 6 , wherein the step of injecting the repair fluid includes injecting the repair fluid during a fracking operation. 
     
     
         8 . The method of  claim 6 , wherein the repair fluid is a stem pack grease. 
     
     
         9 . The method of  claim 6 , wherein the repair fluid contains Tetrafluoroethylene.