Polymer-Lined Mechanically Lined Pipe for Wrinkle-Free Reeling
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Solution Overview
Problem
Mechanically lined pipes (MLPs) face issues with wrinkling and buckling of the corrosion-resistant alloy (CRA) liner during reeling and unreeling operations, leading to complex and costly installation procedures and potential damage, especially when pressurization methods require fresh water and increase project execution time.
Innovation Solution
A mechanically lined pipe with a polymer liner that presses the metallic liner against the host pipe's inner surface, reducing the risk of wrinkling by exerting a contact pressure of at least 3 bar, allowing reeling and unreeling at atmospheric pressure, and using a polymer liner with a larger outer diameter that is reduced to fit inside the pipe, expanding to press the metallic liner securely in place.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the CRA liner thickness is increased to prevent wrinkling during reeling operations, then the liner's resistance to buckling and wrinkling improves, but the cost and complexity of the pipe increases
Solution Approach 1:
A polymer liner is introduced as an intermediary element between the CRA liner and the host pipe. This polymer liner acts as a mediator that provides mechanical support during reeling operations, preventing the CRA liner from wrinkling or buckling without requiring the CRA liner itself to be thicker. The polymer liner absorbs the mechanical stresses during installation, allowing the CRA liner to maintain its protective function with optimal thickness.
Solution Approach 2:
The solution employs a composite structure consisting of multiple layers: the host pipe, the CRA liner, and the polymer liner. This composite material approach combines the corrosion resistance of the CRA liner with the mechanical flexibility and support of the polymer liner, achieving both wrinkle prevention and cost-effectiveness through material combination rather than increasing single-layer thickness.
2Reliability
If pressurization with fresh water is applied during reeling operations to prevent CRA liner detachment, then the risk of buckling and wrinkling reduces, but the project execution time and cost increase
Solution Approach 1:
The polymer liner is installed beforehand during the pipe manufacturing process, before the pipe is shipped to the installation site. This preliminary action ensures that the CRA liner is already secured and protected against detachment and wrinkling during subsequent reeling operations, eliminating the need for time-consuming pressurization procedures during installation and reducing project execution time.
Solution Approach 2:
The polymer liner provides self-supporting functionality during reeling operations. By being pre-installed and expanding to contact the host pipe, the polymer liner automatically prevents CRA liner detachment and wrinkling without requiring external pressurization systems or fresh water, making the system self-sufficient during installation.
3Reliability
If pressurization systems are used during reeling operations to maintain CRA liner integrity, then the risk of wrinkling reduces, but the complexity and cost of installation procedures increases
Solution Approach 1:
The complex pressurization system is extracted and removed from the installation process. Instead of requiring external pressurization equipment and procedures, the polymer liner provides inherent mechanical support during reeling operations, simplifying the installation procedure while maintaining CRA liner integrity through the pre-installed polymer support structure.
4Stability of the object's composition
If the CRA liner thickness is increased to prevent wrinkling, then the liner's structural stability improves, but the cost of the pipe increases
Solution Approach 1:
The polymer liner serves as a mediator that provides the mechanical stability needed during reeling operations, allowing the CRA liner to maintain its optimal thickness. The polymer liner absorbs the mechanical stresses and supports the CRA liner structure, preventing wrinkling without requiring additional CRA material, thus reducing the quantity of expensive CRA liner material needed while maintaining structural stability.
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 solution minimizes the risk of wrinkling, reduces the complexity and cost of the laying process, and allows for the use of seawater, making it more feasible for subsea pipeline installations without the need for pressurization, thus enhancing the reliability and economic viability of MLPs.
Implementation Method 1
a polymer liner which presses the metallic liner against the inner surface of the host pipe
Data Source
AI summary
A mechanically lined pipe including a host pipe having an inner surface which is lined with a metallic liner, the metallic liner having an inner surface which is lined with a polymer liner which presses the metallic liner against the inner surface of the host pipe, as well as to methods of reeling and unreeling the mechanically lined pipe. A method of making a mechanically lined pipe having an internal polymer liner, the mechanically lined pipe including a host pipe having an inner surface which is lined with a metallic liner, the method including the steps of: (a) providing a mechanically lined pipe having an internal diameter, (b) providing a polymer liner having an outer diameter which is greater than the internal diameter of the mechanically liner pipe, (c) reducing the outer diameter of the polymer liner such that it is less than the internal diameter of the mechanically liner pipe, (d) inserting the polymer liner into the mechanically lined pipe, and (e) allowing the polymer liner to expand such that it presses the metallic liner against the inner surface of the host pipe.