Asbestos Pipe Vault Encapsulation for No-Excavation Repair
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Solution Overview
Problem
The removal of asbestos-containing asbestos cement (AC) pipes poses health risks and requires extensive excavation and hazardous waste disposal, which is costly and disruptive, especially in challenging environments like coastal communities with high water tables.
Innovation Solution
A method and system for in-place encapsulation of AC pipes using a scribing head to separate the pipe into halves, followed by application of a moisture-activated expanding urethane foam to reinforce and encapsulate the pipe, allowing a new HDPE pipe to be installed without excavation, thus eliminating the need for hazardous waste disposal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AC pipes are removed and replaced with new pipes, then the piping system can be updated and functionality restored, but extensive excavation is required, construction costs increase, and asbestos exposure risks arise
Solution Approach 1:
The patent applies nesting by installing a new HDPE pipe inside the existing AC pipe, creating a nested configuration where the new functional pipe is placed within the old pipe structure. This eliminates the need for excavation and pipe removal, as the new pipe is nested within the existing infrastructure, thereby restoring functionality while avoiding complex construction processes and asbestos exposure risks.
2Object-affected harmful factors
If AC pipes are manually dismantled and asbestos debris is collected, then asbestos can be disposed of according to regulations, but the process requires considerable time, labor, and creates potential for asbestos scattering
Solution Approach 1:
The patent extracts the problematic AC pipe material from the system by having it broken up and left in place, while extracting only the necessary function through the new HDPE pipe installation. The asbestos-containing material is effectively taken out of the functional system and isolated, eliminating the need for manual dismantling and asbestos debris collection, thereby controlling asbestos exposure while maintaining productivity.
Solution Approach 2:
The patent converts the harmful AC pipe material into a beneficial containment structure by leaving it in place and using it as the outer containment for the new pipe. The asbestos pipe, rather than being removed as a hazard, becomes part of the solution by serving as the outer structural element, eliminating dismantling work while maintaining asbestos control.
3Reliability
If extensive excavation is performed to remove AC pipes, then new pipes can be installed, but construction costs increase and community disruption occurs
Solution Approach 1:
The patent inverts the conventional approach by not removing the old pipe but rather installing the new pipe inside it. Instead of excavating to remove the AC pipe and then installing the new pipe, the method pushes the new HDPE pipe through the existing AC pipe from one end, completely inverting the sequence and methodology of traditional pipe replacement, thereby eliminating excavation and community disruption.
4Ease of manufacture
If AC pipes are left in place without removal, then excavation and disposal costs are avoided, but asbestos may still contaminate soil and water table
Solution Approach 1:
The patent introduces an intermediary substance (expanding foam) that fills the annular space between the new HDPE pipe and the existing AC pipe. This foam acts as a mediator that seals and contains the asbestos-containing AC pipe material, preventing potential contamination of soil and water table while allowing the new pipe to function. The intermediary foam creates a barrier that eliminates the harmful effects of leaving the AC pipe in place.
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 system safely and economically disposes of asbestos debris by keeping the AC pipes in place, minimizing disruption, avoiding hazardous material handling, and reducing costs associated with excavation and disposal.
Implementation Method 1
application of a moisture-activated expanding urethane foam to reinforce and encapsulate the pipe
Data Source
AI summary
A vault system is provided to allow capture and encapsulation of debris generated during the rehabilitation of asbestos concrete (AC) pipe allowing the debris to remain in place while rendering the asbestos containing material harmless, in a manner that protects the ecosystem and saves huge amounts of money lost to packaging, shipping and disposal of this debris. The vault system provides for containment and encapsulation of the AC pipe repair debris in place, eliminating hazardous material disposal requirements, and the costs associated therewith.