Method and apparatus for forming a lined conduit

Abstract

A lined conduit formed by decorrugating a corrugated liner conduit inside a first conduit is described. A method and apparatus for forming the lined conduit are also described. The corrugated liner conduit may be positioned inside the first conduit. Each end portion of the corrugated liner conduit may be coupled to a hydraulic expander. Each hydraulic expander may include a hydraulic cylinder. Each hydraulic cylinder may include a piston rod with an opening along the length of the piston rod. The corrugated liner conduit may be evacuated through a valve assembly coupled to the passageway in one of the piston rods. The evacuated corrugated liner conduit may be pressurized with fluid from a fluid source coupled to the valve assembly. Pressurizing the corrugated liner conduit may expand corrugations in the corrugated liner conduit to form a decorrugated liner in the first conduit.

1 . A lined conduit, comprising:
 a first conduit with an inner surface; and   a liner connected to the inner surface of the first conduit, wherein the liner comprises a material that has been corrugated and decorrugated, and wherein a thickness of the liner before corrugation is at most 50 mil.   
     
     
         2 . The lined conduit of  claim 1 , wherein the liner is hoop compressed against the first conduit to couple the liner to the first conduit. 
     
     
         3 . The lined conduit of  claim 1 , wherein the liner comprises a metal. 
     
     
         4 . The lined conduit of  claim 1 , wherein the first conduit comprises carbon steel and the liner comprises stainless steel. 
     
     
         5 . The lined conduit of  claim 1 , wherein the thickness of the liner before decorrugation is at most 40 mil. 
     
     
         6 . The lined conduit of  claim 1 , wherein the thickness of the liner before decorrugation is at most 30 mil. 
     
     
         7 . The lined conduit of  claim 1 , wherein the liner is electrically coupled to the inner surface of the first conduit. 
     
     
         8 . The lined conduit of  claim 1 , wherein the liner is frictionally coupled to the inner surface of the first conduit. 
     
     
         9 . The lined conduit of  claim 1 , wherein the liner comprises a conduit that has been corrugated, inserted into the first conduit, and decorrugated while in the first conduit. 
     
     
         10 . The lined conduit of  claim 1 , wherein the liner comprises a decorrugated, hoop compressed conduit. 
     
     
         11 . The lined conduit of  claim 1 , wherein the liner comprises a conduit that has been corrugated and then decorrugated, and wherein an outer diameter of the liner prior to corrugation is larger than an inner diameter of the first conduit. 
     
     
         12 . The lined conduit of  claim 1 , wherein the liner has been hydraulically decorrugated inside the first conduit. 
     
     
         13 . The lined conduit of  claim 1 , wherein the liner has a substantially smooth inner surface. 
     
     
         14 . The lined conduit of  claim 1 , wherein the thickness of the liner is less than ¼ of the thickness of the first conduit. 
     
     
         15 . The lined conduit of  claim 1 , wherein the liner comprises a conduit that has been corrugated and then decorrugated, wherein the outer diameter of the liner conduit after decorrugation is substantially the same or less than the outer diameter of the liner conduit prior to corrugation. 
     
     
         16 . The lined conduit of  claim 1 , wherein the liner comprises a conduit that has been corrugated and decorrugated, wherein the corrugation comprises a plurality of ridges. 
     
     
         17 . The lined conduit of  claim 1 , wherein the liner comprises a conduit that has been corrugated and decorrugated, wherein the corrugation comprises a plurality of longitudinal ridges. 
     
     
         18 . The lined conduit of  claim 1 , wherein the liner comprises a conduit has been corrugated and decorrugated, wherein the corrugation comprises a plurality of compressed ridges. 
     
     
         19 . The lined conduit of  claim 1 , wherein the liner comprises a spiral welded conduit. 
     
     
         20 - 110 . (canceled) 
     
     
         111 . A lined conduit made by a method comprising:
 providing a corrugated liner conduit inside a first conduit, wherein a thickness of the liner before corrugation is at most 50 mil;   evacuating the corrugated liner conduit after providing the corrugated liner conduit to the inside of the first conduit; and   decorrugating the corrugated liner conduit while the corrugated liner conduit is inside the first conduit.