Rigid Shells for Underwater Pipe Joint Insulation
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Solution Overview
Problem
The existing 'Field Joint Coating' technique for connecting underwater fluid transport pipes is time-consuming, prone to adhesion issues, and lacks flexibility, particularly when using injection molding, which affects the durability of the molded joint and requires extensive production time.
Innovation Solution
The method involves using rigid shells made of the same material as the external insulating coating, which are welded together and to the pipe ends without coating, ensuring continuity and using electro-fusion or laser welding for sealing, reducing the connection time and eliminating adhesion problems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Field Joint Coating technique is used to connect pipe sections, then the insulating coating continuity is maintained, but the connection time is long (20-30 minutes per operation)
Solution Approach 1:
The insulating coating is segmented into modular shell pieces that can be independently prepared, transported, and assembled. Each shell corresponds to a specific pipe section interface, allowing pre-fabrication and rapid assembly without time-consuming field application procedures.
Solution Approach 2:
The insulating shells are prepared in advance during factory production, including application of the insulating coating and integration of heating elements. This preliminary preparation eliminates the need for time-consuming field coating application and allows immediate installation at the connection point.
2Reliability
If multiple layers of polymer materials are applied for Field Joint Coating, then the insulation is restored, but the application process is complex and time-consuming
Solution Approach 1:
Multiple functional layers (insulation material, heating elements, bonding agents, protective coatings) are merged into a single integrated shell component manufactured in the factory. This consolidation eliminates the need for sequential field application of multiple separate layers and their associated complex procedures.
3Ease of manufacture
If the insulating coating is removed from pipe ends for welding, then the steel ends can be connected, but the exposed areas require extensive re-coating
Solution Approach 1:
The insulating shells are pre-assembled on the pipe sections in the factory before shipment, eliminating the need for time-consuming field re-coating operations. The shells are installed once at the connection point, restoring insulation continuity without requiring extensive re-coating of exposed areas.
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 significantly reduces connection time to approximately 3 minutes, ensures a leak-tight seal, and is applicable to various thermoplastic materials and dimensions, offering improved flexibility and durability compared to traditional techniques.
Implementation Method 1
a heating element, in use melting the thermoplastic material of the external insulating coating, being integrated into each shell
Implementation Method 2
at least one electrical resistance positioned at radial weldable surfaces which are brought into contact, during the sealing stage of the shells, with the external insulating coating of the unitary conduit elements
Data Source
Figure 1~5
Figure 4
Figure 6A~6C
AI summary
The invention relates to a method for connecting two individual elements (4, 4') of a fluid transport pipe, each individual pipe element being made from metal alloy and being coated with an external insulating coating (6, 6') made from a thermoplastic material, except one end portion of the element that is not coated with the external insulating coating. The method comprises: a step of welding the two individual pipe elements which are placed end to end at the coating-free end portions thereof; a step of mechanically assembling at least two rigid shells (14, 16) on the coating-free end portions of the individual pipe elements, said rigid shells being made from a thermoplastic material; and a step of maintaining the shells leaktight relative to the external insulating coating of the two individual pipe elements.