Pipe Replacement via Cable Extraction and Fluid Support

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Solution Overview

Problem

Existing methods for replacing pipes, such as trenching and trenchless techniques, are costly, disruptive, and inefficient, especially when dealing with smaller pipes or those made of lead, and often leave the old pipe in place, potentially contaminating groundwater and requiring significant force to remove.

Innovation Solution

A method involving locating the ends of the existing pipe, injecting a settable fluid to provide support, and using a flexible cable connected to a component to pull out the old pipe while inserting a new one, utilizing a winch to apply a manageable force and minimize deformation and friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a mole is used to create a hole through earth for pipe replacement, then trenchless replacement is achieved, but large entry and exit holes must be dug creating considerable mess

Engineering Contradiction:
Improvemess created by excavationVSAvoidcomplexity of entry and exit hole preparation
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention extracts the problematic old pipe from the ground through a small access hole using a retrieval device that grabs and pulls the pipe out, rather than digging a large trench or creating large entry/exit holes. This removes the harmful excavation mess while achieving pipe replacement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses a retrieval device as an intermediary tool that passes through a small access hole, grabs the old pipe, and extracts it to the surface. This intermediary mechanism enables pipe removal without direct large-scale excavation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If a splitter is used to force the existing pipe outwardly, then the replacement pipe can be pulled through, but a relatively large force is required which can deform the pipe

Engineering Contradiction:
Improveefficiency of pipe replacementVSAvoidforce required to split and remove pipe
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

Instead of forcing the pipe outwardly with a splitter that requires large forces, the invention inverts the approach by using a retrieval device to grab and pull the pipe out through a small hole. This reverses the force direction and reduces the required force while maintaining productivity.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention changes the parameter of force application from high-magnitude outward forcing to lower-magnitude pulling through a small hole. The retrieval device is designed to grip and extract the pipe with manageable forces that avoid excessive deformation.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If the existing pipe is left in place after splitting, then the replacement pipe can be installed, but the old pipe remains potentially contaminating groundwater

Engineering Contradiction:
Improveease of pipe replacementVSAvoidgroundwater contamination from old pipe
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the old pipe from the ground through a small access hole using a retrieval device, completely removing it from the environment. This eliminates the harmful factor of groundwater contamination from abandoned lead pipes while maintaining ease of replacement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention discards the old pipe by extracting and removing it from the ground through a small hole, preventing it from remaining in place to contaminate groundwater. The retrieved pipe can be properly disposed of or recovered for recycling.

Inventive Principle:
Principle #34Discarding and recovering

4Object-affected harmful factors

If directional drilling technique is used for trenchless pipe replacement, then pipe can be replaced without digging trench, but the technique is very expensive

Engineering Contradiction:
Improvedisruption from trenchingVSAvoidcost of replacement
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The invention uses a simple, inexpensive retrieval device that can be inserted through a small access hole to grab and extract the old pipe. This disposable or reusable simple tool achieves trenchless replacement at a fraction of the cost of expensive directional drilling equipment.

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

Solution Approach 2:

The invention changes the approach from expensive directional drilling to a simple mechanical retrieval process through a small hole. This parameter change from high-tech drilling to low-tech retrieval dramatically reduces cost while maintaining the benefit of minimal ground disruption.

Inventive Principle:
Principle #35Parameter changes

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 method efficiently removes the old pipe while inserting a new one, reducing environmental contamination and minimizing disruption, with forces typically less than 2 tonnes, suitable for most pipe materials and configurations, including bends, and avoiding the need for extensive excavation.

Implementation Method 1

injecting a settable fluid into the existing pipe, and allowing the settable fluid to set within the existing pipe into a material which is sufficiently rigid to provide support

Methodology Applied
Scientific EffectSetting: Phase Change

Data Source

PatentEP2100071B1Method for replacing pipes, and apparatus therefor
Publication Date: 2013.05.22 CILLIERS JACOBUS HENDRIK
  • EP2100071B1 patent drawingFigure 1~3

AI summary

This invention relates to a method for replacing pipes, and an apparatus therefor. The method utilises a cable which is passed along an existing pipe. The cable is connected to a component at the end of the pipe, the component also being connected to a length of replacement pipe. The cable is pulled whereby the existing pipe is removed and the replacement pipe inserted in its place. The invention is expected to achieve its greatest utility as a method and apparatus for replacing pipes carrying water or gas to domestic and commercial properties.