Shear increasing system

Abstract

A piping system employs a friction layer of windings, beads or pellets placed between insulation layers and/or on the outermost layer, that being the insulation layer if no jacket is employed or the jacket if it is employed. The windings, beads or pellets are wrapped or applied while the layer is uncured or warm so as to embed themselves into the surface and create a uneven, bumpy or undulating surface. The resulting product increases friction both internally and externally to better restrain or inhibit pipe movement in underground, marine, or subsea applications or provide restraint to the surrounding environment (earth, concrete, etc.).

What is claimed is: 
     
         1 . A steel pipe having an outer surface and a fluid conduit comprising:
 an insulation layer enveloping the outer surface and of a material selected from the group consisting of: polyurethane, foamed polyurethane, polypropylene, glass syntactic polyurethane, and glass syntactic polypropylene;   a jacket enveloping the insulation layer of a high density polyethylene;   an outer layer on the jacket and having an undulating surface of at least one of a plastic wire, a plastic mesh, a metal mesh, beads, and pellets.   
     
     
         2 . The pipe of  claim 1  wherein the high density polyethylene is fiberglass reinforced. 
     
     
         3 . The pipe of  claim 1  wherein the high density polyethylene layer has a bonding film for attachment to the insulation layer. 
     
     
         4 . The pipe of  claim 1  wherein the jacket is extruded on to the insulation layer. 
     
     
         5 . The pipe of  claim 4  wherein the outer layer is applied to the jacket while the jacket is cooling 
     
     
         6 . The pipe of  claim 1  further comprising an anticorrosion layer directly on the outer surface. 
     
     
         7 . The pipe of  claim 1  wherein the plastic is polyethylene or polypropylene. 
     
     
         8 . The pipe of  claim 1  wherein the beads are polyethylene or polypropylene. 
     
     
         9 . The pipe of  claim 1  wherein the wire has a diameter of from 1/16 inch to ½ inch. 
     
     
         10 . The pipe of  claim 1  wherein the bead has a diameter of from 1/16 inch to ½ inch. 
     
     
         11 . The pipe of  claim 1  wherein the outer layer comprises a random or even arrangement of beads. 
     
     
         12 . The pipe of  claim 1  wherein the pipe has numerous segments connected together at field joints further comprising a final jacket over each field joint in tight contact with the outer layer. 
     
     
         13 . The pipe of  claim 12  wherein the final jacket is heat shrunk to the outer layer. 
     
     
         14 . A method for insulating a steel pipe having an outer surface and a fluid conduit comprising:
 molding an insulating material to the outer surface to form an insulation layer;   extruding high density polyethylene on the insulation layer to form a jacket; and   applying an outer layer to the jacket while the jacket is cooling, the outer layer having an undulating surface of at least one of a plastic wire, a plastic mesh, a metal mesh, beads, and pellets.   
     
     
         15 . The method of  claim 14  wherein the applying step comprises winding the plastic wire, plastic mesh or metal mesh spirally about the jacket. 
     
     
         16 . The method of  claim 14  wherein the applying step comprises laying the beads or pellets in a spiral pattern about the jacket. 
     
     
         17 . The method of  claim 14  wherein the applying step comprises randomly laying the beads or pellets to the jacket. 
     
     
         18 . The method of  claim 14  wherein the steel pipe comprises a plurality of segments connected together at field joints further comprising fitting a final jacket over each field joint in tight contact with the outer layer. 
     
     
         19 . The method of  claim 18  further comprising heat shrinking the final jacket to the outer layer. 
     
     
         20 . The method of  claim 14  wherein the insulating material is selected from the group consisting of: polyurethane, foamed polyurethane, polypropylene, glass syntactic polyurethane, and glass syntactic polypropylene