In-situ installable replacement pipeline and method of installation thereof

Abstract

A method of in-situ pipeline replacement in which valves, fittings, and other obstructions are removed from an existing pipeline, a heat-fusible polymer pipeline having an initially deformed configuration less than the existing pipeline diameter is inserted into the remaining portions of the existing pipeline and reformed to substantially conform to the inside diameter of the existing pipeline, heat-fusible fittings are provided to replace removed portions of the existing pipeline and heat-fused to the polymer liner, and transition fittings provided to operably connect the replacement pipeline to those portions of the existing pipeline not within the replacement scope. The completed replacement polymer pipeline creates an operable wetted pressure boundary within the bounds of the replaced existing pipeline.

Having thus described the invention, what is claimed is: 
     
         1 . A method of in-situ pipeline replacement for an existing pipeline comprising the steps of:
 providing replacement pipe having a flexibility limit;   identifying obstructions in the existing pipeline requiring flexibility of the replacement pipe when routed therethrough exceeding the flexibility limit;   providing transition fittings configured to connect the replacement pipe to existing pipeline;   providing access to at least the identified obstructions in the existing pipeline;   removing the identified obstructions from the existing pipeline;   deforming the replacement pipe to a deformed cross-sectional configuration that is less than the internal diameter of the existing pipeline;   installing the replacement pipe in the deformed configuration into the existing pipeline;   reforming the replacement pipe so that the outside diameter of the replacement pipe generally conforms to the internal diameter of the existing pipeline; and   connecting the replacement pipe to a non-replaced portion of the existing pipeline not subject to in-situ replacement using the transition fittings to establish a continuous pressure boundary encompassing the replacement pipe and the non-replaced portion of the existing pipeline.   
     
     
         2 . The method of  claim 1 , wherein the transition fittings are thermally fused to the replacement pipe. 
     
     
         3 . The method of  claim 1 , wherein the transition fittings are mechanically coupled to the replacement pipe. 
     
     
         4 . The method of  claim 1 , wherein the replacement pipe and transition fittings comprise a heat-fusible polymer material. 
     
     
         5 . The method of  claim 4 , wherein the heat-fusible polymer material is high density polyethylene. 
     
     
         6 . A replacement pipeline for a portion of an existing pipeline comprising:
 an existing pipeline having at least a first interface, a second interface, and a portion to be replaced therebetween;   a deformable replacement pipe being deformable to an extent enabling axial insertion thereof into an interior circumference of the portion of the existing pipeline to be replaced and reformable to substantially conform to the interior circumference; and   first and second transition fittings each configured to connect an open end of the replacement pipe to an adjacent open end of the existing pipeline at the first and second interfaces, respectively, thereby creating an integral pressure boundary encompassing the existing pipeline and the replacement pipe.   
     
     
         7 . The replacement pipeline of  claim 6 , further comprising one or more appurtenances operably connected to the replacement pipe in a manner maintaining the pressure boundary between the replacement pipe and the one or more appurtenances. 
     
     
         8 . The replacement pipeline of  claim 7 , wherein the one or more appurtenances comprise fittings, tees, elbows, valves, bends, service connections, and adapters. 
     
     
         9 . The replacement pipeline of  claim 6 , wherein the replacement pipe comprises a heat-fusible polymer material. 
     
     
         10 . A replacement pipeline for a portion of an existing pipeline comprising:
 an existing pipeline;   a replacement pipe being deformable to an extent enabling axial insertion thereof into an interior circumference of the existing pipeline and reformable to substantially conform to the interior circumference, the replacement pipe being internally disposed in a portion of the existing pipeline;   first and second spaced-apart transitions in the existing pipeline defining a replacement boundary therebetween; and   a transition fitting configured to connect the replacement pipe to the existing pipeline at each transition thereby creating an integral pressure boundary encompassing the existing pipeline and the replacement pipe.   
     
     
         11 . The replacement pipeline of  claim 10 , wherein the connection of the transition fitting to the replacement pipe includes fusion connection, adhesive connection, or mechanical connection. 
     
     
         12 . The replacement pipeline of  claim 11 , further comprising one or more appurtenances connected to the replacement pipe in a manner maintaining the pressure boundary between the replacement pipe and the one or more appurtenances. 
     
     
         13 . The replacement pipeline of  claim 12 , wherein the one or more appurtenances comprise fittings, tees, elbows, valves, bends, service connections, and adapters. 
     
     
         14 . The replacement pipeline of  claim 13 , wherein the replacement pipe comprises a heat-fusible polymer material.