Viscoelastic Pipe Lining by Pressure Expansion Without Annular Space

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Solution Overview

Problem

Existing pipe rehabilitation methods require significant investment, large construction site footprints, and are limited in diameter and length, often necessitating hot processes and specialized equipment, which are costly and inefficient.

Innovation Solution

A method involving viscoelastic materials where a tube of smaller diameter is inserted into a pipe, welded in sections, and inflated with liquid pressure to expand and fit snugly within the existing pipe without annular space, allowing for flexible insertion and rehabilitation without heating equipment or specialized machines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If tube stretching or compression methods are used to reduce pipe diameter for insertion, then the pipe can be inserted into the existing pipeline, but large construction site footprints and specialized equipment are required

Engineering Contradiction:
Improvepipe outer diameterVSAvoidconstruction site footprint
Core Design Contradiction:
Length of moving objectVSArea of stationary object

Solution Approach 1:

The invention changes the material parameter from conventional elastic materials to viscoelastic materials, which exhibit time-dependent deformation behavior. This allows the pipe to be inserted at a reduced diameter and then recover to its original diameter within the pipeline without requiring external stretching or compression equipment, thereby eliminating the need for large construction sites and specialized machinery.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical stretching/compression systems (requiring large equipment and space) with an internal pressure system using liquid or gas. The fluid pressure is introduced through the pipe wall to expand the viscoelastic pipe to its original diameter, substituting complex mechanical systems with a simpler hydraulic/pneumatic system that requires minimal space.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If conventional tubing methods with specialized equipment are used, then pipe rehabilitation can be achieved, but costs increase significantly

Engineering Contradiction:
Improvepipe rehabilitation effectivenessVSAvoidimplementation cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention employs a disposable viscoelastic pipe that is inserted in a compressed state and then expanded within the existing pipeline. The pipe serves its function of rehabilitation and then remains in place as the permanent solution, eliminating the need for expensive reusable stretching or compression equipment. The material itself performs the function that would otherwise require costly machinery.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The viscoelastic pipe performs the rehabilitation function itself through its inherent material properties. When inserted in a compressed state and then expanded using simple fluid pressure, the pipe automatically recovers to its original diameter and conforms to the existing pipeline, achieving rehabilitation without requiring external specialized equipment or complex manufacturing processes.

Inventive Principle:
Principle #25Self-service

3Length of moving object

If hot processes are used for pipe rehabilitation, then pipe deformation and insertion can be achieved, but operational complexity increases

Engineering Contradiction:
Improvepipe deformabilityVSAvoidprocess complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The invention replaces thermal processes (heating equipment) with mechanical/viscoelastic processes. The viscoelastic material properties allow the pipe to be deformed and inserted at ambient temperatures, eliminating the need for hot processes and associated heating equipment, thereby reducing operational complexity while maintaining pipe deformability and insertion capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This approach enables efficient pipe rehabilitation with a small site footprint, flexibility in pipe insertion, and no limitations on diameter or length, reducing costs and operational complexity while ensuring reliable pipe diameter restoration.

Implementation Method 1

viscoelastic deformation of the pipe

Methodology Applied
Scientific EffectViscoelastic deformation: Viscoelasticity

Implementation Method 2

filling the pipe with a liquid and pressurizing the liquid until the pipe is inflated so as to press against the pipe

Methodology Applied
Scientific EffectPressure-induced expansion: Pressure Increase

Data Source

PatentEP3743649B1Method for lining a pipe without an annular space
Publication Date: 2023.10.25 AXEO
  • EP3743649B1 patent drawingFigure 1
  • EP3743649B1 patent drawingFigure 2
  • EP3743649B1 patent drawingFigure 3

AI summary

The invention relates to a method for lining, without an annular space, a pipe that has a first diameter and extends substantially in a longitudinal axis, said method being characterised in that it comprises the following steps: inserting (101), into the pipe, by translation in the longitudinal axis, a first tubular portion consisting of a viscoelastic material and having a second diameter smaller than the first diameter, in order to form a tube; juxtaposing (102) a second tubing portion consisting of a viscoelastic material and having a second diameter in line with the tube, along the longitudinal axis; welding (103) the second tubing portion to the tube in order to extend the tube; positioning (104) the tube in the pipe; filling (105) the tube with a liquid and pressurising the liquid until the tube swells such that it press firmly against the pipe; and viscoelastic deformation (106) of the tube.