Induction-Heated Electrofusion Fittings for Leak-Safe Lined Pipe Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrofusion fitting methods for joining lined pipes face challenges in ensuring the integrity of the pipe linings and host pipes, particularly due to the potential for fluid leakage through electrical leads and limitations in closed bevel automatic pipeline welding processes.
Innovation Solution
The method employs electromagnetic induction to energize heating elements within electrofusion fittings, eliminating the need for direct electrical connections by using induction coils to generate heat, which penetrates the heating elements and ensures a reliable weld between the fitting and the pipe lining without compromising the integrity of the joint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical leads are extended through the electrofusion fitting to supply power to heating coils, then the heating process can be completed, but a potential leak path is created for pressurized fluid
Solution Approach 1:
The patent removes electrical leads from the internal flow path of the electrofusion fitting. Instead of routing leads through the fitting's interior where they could create leak paths, the leads are positioned externally or in a manner that does not compromise the sealing integrity of the joint.
Solution Approach 2:
The patent introduces a sealed conduit or protective barrier as an intermediary between the electrical leads and the pressurized fluid environment. This intermediary allows electrical power to be delivered to the heating coils while maintaining the fluid-tight integrity of the fitting.
2Ease of operation
If open bevel weld preparation is used to access heating coils, then electrical power can be delivered, but the method has restricted use in modern pipeline welding
Solution Approach 1:
The patent transitions from a two-dimensional approach (open bevel preparation on the pipe surface) to a three-dimensional approach by delivering electrical power through the depth of the fitting structure or through the wall thickness, enabling compatibility with closed bevel welding configurations.
Solution Approach 2:
The patent designs an electrical power delivery system that can accommodate multiple welding configurations (both open bevel and closed bevel) and different fitting types, making the system universally applicable across modern pipeline welding practices.
3Ease of manufacture
If electrical leads are routed through the electrofusion fitting, then heating coils can be energized, but the manufacturing and testing complexity increases
Solution Approach 1:
The patent incorporates electrical leads into the electrofusion fitting during the manufacturing process itself, rather than installing them separately during field operations. This preliminary integration simplifies the overall manufacturing process and reduces field installation complexity.
Solution Approach 2:
The patent combines the electrical lead routing with the fitting's structural design, integrating the electrical components into the overall fitting architecture rather than treating them as separate additions. This merging reduces the number of discrete components and assembly steps.
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 enhances the reliability of the fusion process, reduces the risk of fluid ingress, simplifies the manufacturing and testing of electrofusion fittings, and allows for more efficient pipeline welding by eliminating the need for precise electrical contact points and reducing material costs.
Implementation Method 1
supplying electrical power to an induction coil to thereby heat the heating element by electromagnetic induction
Implementation Method 2
locating an induction coil within a bore of the electrofusion fitting in the vicinity of the heating element, and supplying electrical power to the induction coil to energise the heating element by electromagnetic induction
Implementation Method 3
causes the fitting and the lining in the vicinity of the coils to melt and fuse together
Data Source
Figure 1~2
Figure 3~4
AI summary
A method of creating a weld between a liner of a section of lined pipe and an electrofusion fitting. The fitting comprises at least one heating element, which is suitably disposed on or in an outer surface of the electrofusion fitting and is electrically isolated from an inner surface of the fitting. The method comprises locating an end of the electrofusion fitting within an end of the section of lined pipe, locating an induction coil within a bore of the electrofusion fitting in the vicinity of the at least one heating element, and supplying electrical power to the induction coil to energise the at least one heating element by electromagnetic induction.