Liner assembly for pipeline repair and methods of installing same

Abstract

A liner assembly for pipeline repair and methods of installing same. The liner assembly generally comprises an outer tubular liner, an inner malleable inflatable bladder positioned longitudinally within said liner, and a generally non-stretchable strap positioned longitudinally within the malleable inflatable bladder. The generally non-stretchable strap restricts longitudinal over-expansion during positioning and inflation of the liner assembly within a pipeline.

1 . A liner assembly for pipeline repair comprising:
 an outer tubular liner;   an inner malleable inflatable bladder positioned longitudinally within said liner; and   a generally non-stretchable strap positioned longitudinally within the malleable inflatable bladder, said strap restricting longitudinal over-expansion during positioning and inflation of the liner assembly within a pipeline.   
     
     
         2 . The liner assembly of  claim 1 , further comprising a protective sheath surrounding said liner. 
     
     
         3 . The liner assembly of  claim 2 , wherein said plastic sheathing is fitted to the outer circumference of the outer felt liner tube. 
     
     
         4 . The liner assembly of  claim 2 , wherein said plastic sheathing comprises a first longitudinal edge and a second longitudinal edge, said second longitudinal edge being adapted to overlap said first longitudinal edge. 
     
     
         5 . The liner assembly of  claim 4 , wherein the overlap is tack welded. 
     
     
         6 . The liner assembly of  claim 1 , further comprising a release layer positioned between said liner and said bladder. 
     
     
         7 . The liner assembly of  claim 1 , wherein said strap is formed of vinyl. 
     
     
         8 . A liner kit for installing a liner in a pipeline, the kit comprising:
 the liner assembly as defined in  claim 1 ;   a pair of non-stretchable retaining sleeves for insertion into each end of a liner assembly for preventing radial over-expansion during inflation of the liner assembly;   a pull block for insertion into one end of the liner assembly, allowing for a pulling device to be attached to the liner assembly;   an inflation block for insertion into a second end of the liner assembly, allowing for inflation of the malleable inflatable bladder; and   a resin kit comprising components for preparing a resin for wetting said felt liner prior to installation.   
     
     
         9 . The liner kit of  claim 8 , wherein said resin is an epoxy resin. 
     
     
         10 . The liner kit of  claim 8 , wherein said pair of retaining sleeves is made of vinyl. 
     
     
         11 . A method of installing a prepared liner assembly in a pipeline, comprising the steps of:
 pulling a prepared liner assembly carrying a wetted liner into position in said pipeline, said liner assembly including an outer felt liner tube, an inner malleable inflatable bladder positioned longitudinally within said felt liner tube, and a non-stretchable strap positioned longitudinally within the inflatable bladder, said non-stretchable strap being fixed to each end of said liner assembly to restrict longitudinal over-expansion during positioning and inflation of the liner assembly within said pipeline;   introducing fluid into said malleable inflatable bladder so that said malleable inflatable bladder expands to bring said outer felt liner tube into firm contact with interior surfaces of the pipeline;   maintaining said liner assembly in an inflated condition for a time period sufficient for the outer felt liner tube to cure;   deflating said malleable inflatable bladder and retrieving said malleable inflatable bladder from the liner assembly.   
     
     
         12 . A liner assembly for installing a liner at a junction between a main pipe and a lateral pipe, said liner assembly comprising:
 a malleable inflatable bladder assembly for carrying a liner, said malleable inflatable bladder assembly including a main portion and a lateral portion;   a flow through carrier contained within said main portion; and   a non-stretchable strap within said lateral portion,   wherein said non-stretchable strap is fixed at one end to said flow through carrier contained in said main portion, and adapted on an opposing end to be fixed to the end of said lateral portion of said liner assembly during preparation for installation, said non-stretchable strap serving to restrict longitudinal over-expansion of the lateral portion during positioning and inflation of the liner assembly within a pipeline.   
     
     
         13 . The liner assembly of  claim 12  wherein said malleable inflation bladder further comprises a release plastic surrounding said lateral portion, for placement between said lateral portion and said liner. 
     
     
         14 . The liner assembly of  claim 12 , wherein said non-stretchable strap is vinyl. 
     
     
         15 . The liner assembly of  claim 12 , wherein said flow through carrier extends through said main portion and further comprises on each end anchors for attachment of installation and retrieval cables. 
     
     
         16 . A method of installing a liner having main and lateral portions at a junction between main and lateral pipes, said method comprising the steps of:
 pulling a prepared liner assembly into said pipeline, said liner assembly comprising a malleable inflatable bladder assembly for carrying a wetted liner, said malleable inflatable bladder assembly including a main portion and a lateral portion, said main portion containing a flow through carrier, said lateral portion containing a non-stretchable strap extending from said flow through carrier to a sealed end of the lateral portion,   said non-stretchable strap serving to restrict longitudinal over-expansion of the lateral portion during positioning and inflation of the liner assembly within a pipeline,   introducing fluid into said malleable inflatable bladder assembly to inflate said assembly so that said assembly expands to bring said wetted liner into firm contact with interior surfaces of the main and lateral pipes and conform said wetted liner to the shape of said junction;   maintaining said malleable inflatable bladder assembly in an inflated condition for a time period sufficient for said wetted liner to cure;   deflating said malleable inflatable bladder assembly; and   retrieving said bladder assembly from said pipeline by pulling said bladder assembly from said liner.