Pipe-in-Pipe Hole Sealing With Friction-Welded Plug Alignment
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Solution Overview
Problem
Existing methods for sealing holes in pipe-in-pipe structures, particularly in subsea pipelines, are time-consuming and prone to leakage, as they require force-fitting and welding of plugs, which can be inefficient and risky, especially when managing pressure and composition in the annulus for thermal insulation and maintenance.
Innovation Solution
A method and apparatus utilizing a sealed chamber with a friction-welding process to insert and secure a spinning plug into the hole, allowing for pressure and composition adjustment within the chamber, ensuring a gas-tight seal by friction-taper plug welding, which maintains alignment and handles torque loads through a clamping system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If force-fitting and welding of plugs is used to seal holes in pipe-in-pipe structures, then the hole can be sealed, but the process is time-consuming and prone to leakage
Solution Approach 1:
The plug is pre-aligned and positioned within the sealed chamber before the welding process begins. The clamping system pre-positions the plug against the hole, ensuring proper alignment before welding commences, which eliminates time-consuming alignment adjustments during the sealing process
Solution Approach 2:
The sealed chamber acts as an intermediary environment that isolates the welding process from the external environment. This controlled chamber allows for efficient friction-welding while preventing leakage, and the clamping system serves as an intermediary mechanism to maintain plug alignment during the welding operation
2Reliability
If force-fitting and welding of plugs is used to seal holes, then sealing can be achieved, but the risk of leakage increases
Solution Approach 1:
The sealed chamber serves as a protective intermediary that contains the welding process and prevents external contaminants from affecting the seal. This controlled environment significantly reduces the risk of leakage by isolating the critical sealing operation from potential sources of contamination
Solution Approach 2:
The invention replaces the traditional force-fitting mechanical sealing method with friction-welding, which creates a more reliable metallurgical bond. This substitution eliminates the gaps and imperfections inherent in force-fitted plugs, thereby reducing leakage risk
3Productivity
If a sealed chamber with friction-welding is used, then sealing efficiency improves, but device complexity increases
Solution Approach 1:
The sealed chamber is designed to perform multiple functions: it contains the welding process, maintains alignment of the plug, provides a controlled environment for welding, and facilitates easy removal after sealing. This multi-functionality justifies the added complexity by consolidating several operations into a single integrated system
Solution Approach 2:
The clamping system incorporates dynamic elements that allow for quick adjustment and release. The system can be rapidly assembled, positioned, and removed, which minimizes the time penalty associated with the more complex device. The dynamic nature of the clamping mechanism enables fast operation despite the increased structural complexity
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 significantly reduces the time and risk of leakage by ensuring a secure, gas-tight seal while maintaining pressure and composition control, enhancing the efficiency of thermal management and maintenance operations in subsea pipelines.
Implementation Method 1
friction-welding a spinning plug into the hole
Data Source
AI summary
A method of sealing a hole in a wall of a hollow structure comprises providing a sealed chamber that is external to the structure and that is in fluid communication with an internal space of the structure via the hole. The structure may be a pipe-in-pipe structure and the internal space may be an annulus between outer and inner pipes. Fluid flows through the hole into or out of the chamber as the pressure and/or composition of fluid in the internal space is adjusted. Then, a plug is spun and friction-welded into the hole. The plug is inserted into the hole from within the chamber.