Anisotropic Pipe Liner Creep Resistance
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Solution Overview
Problem
Reinforced pipes used in underground exploration and transportation face issues with 'creep' due to heat and pressure, leading to degradation and loss of structural support from metal jackets, which existing solutions like polymeric films fail to address effectively.
Innovation Solution
An anisotropic pipe liner is developed with a combination of rigid monofilament fill strands and less rigid warp strands, specifically using 220 denier, 34 thread warp strands and polyester monofilament fill strands, woven in a plain pattern with a hot melt fusion selvage, providing longitudinal flexibility and lateral stiffness to prevent buckling and degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal jacket is used to provide structural support, then the pipe gains strength and stability, but the pipe becomes susceptible to creep under heat and pressure, leading to degradation and loss of structural support
Solution Approach 1:
The patent applies composite materials by combining a metal jacket with a polymeric creep restriction layer. The metal jacket (steel or fiberglass) provides structural strength and stability, while the polymeric layer (biaxially-oriented polyethylene terephthalate or similar materials) restricts creep under heat and pressure. This composite structure allows the pipe to maintain both strength and reliability in subterranean environments.
2Reliability
If a polymeric film is used to restrict creep of the metal jacket, then creep resistance is improved, but the solution proves ineffective in preventing degradation and maintaining structural support
Solution Approach 1:
The patent combines the polymeric creep restriction layer with a metal jacket to create an effective composite structure. The metal jacket restores and maintains structural support capability while the polymeric layer effectively restricts creep. Together, they solve both problems: the metal provides strength that polymeric films alone cannot provide, while the polymeric layer provides creep resistance that metal alone cannot provide.
3Adaptability or versatility
If woven metal jackets are used to permit limited flexing, then the pipe gains flexibility, but separation between metal jacket plates or weave occurs during creep, causing loss of structural support
Solution Approach 1:
The patent introduces a polymeric creep restriction layer as an intermediary between the inner and outer pipe layers, positioned to work in conjunction with the metal jacket. This intermediary layer prevents separation of metal jacket components during creep by providing continuous restraint, while allowing the metal jacket to maintain its woven or plated structure for flexibility.
4Strength
If the pipe is made structurally rigid to prevent collapse, then strength is improved, but the pipe loses flexibility needed for underground exploration and collection
Solution Approach 1:
The patent uses composite materials comprising a metal jacket for structural rigidity and collapse prevention, combined with a polymeric creep restriction layer that maintains flexibility. The metal jacket provides the necessary strength to prevent collapse under external loads, while the overall composite structure with the polymeric layer allows limited flexing needed for underground installation and adaptation to varying subsurface conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The anisotropic pipe liner effectively resists creep, maintaining structural integrity and allowing for easy rolling during storage and transportation, while withstanding heat and pressure, thus extending the lifespan of the pipe.
Implementation Method 1
a hot melt fusion selvage
Data Source
AI summary
A pipe including an inner layer, an outer layer, a jacket layer, and an anisotropic layer positioned between the jacket and outer layers is provided. The anisotropic layer is formed from weaving a number of more rigid, monofilament fill strands and a number of less rigid multifilament warp strands. The fill strands may be formed from single, six hundred-ten (610) denier polyester filament while the warp strands may be formed from a series of two hundred-twenty (220) denier polyester threads. The anisotropic layer permits limited rotation of the inner and outer pipe layers without inserting into the gaps formed by the jacket layer when exposed to intense heat and pressure and is not subjected to significant creep during use.