Wedging Groove Pipe Joint Structure Without Welded Rings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mechanical couplings for joining pipe elements are limited in withstanding loads such as internal pressure and axial tensile forces, requiring external welded rings to achieve full pipe strength, which complicates fabrication and increases costs.
Innovation Solution
The design of pipe elements with specific angled grooves and arcuate projections allows for improved mechanical engagement without external rings, enhancing axial load distribution and internal pressure performance through optimized sub-surface and mating surface angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If external welded rings are used to engage with coupling keys, then the joint can withstand full pipe tensile strength and internal pressure loads, but the fabrication complexity increases and costs increase due to welding requirements
Solution Approach 1:
The groove is directly formed in the pipe element sidewall itself, merging the groove function with the pipe structure. This eliminates the need for separate external welded rings, thereby reducing fabrication complexity while maintaining the mechanical engagement capability with coupling keys to withstand full pipe tensile strength and internal pressure loads.
2Reliability
If external welded rings are used to provide mechanical engagement, then the internal pressure performance and axial tensile loading limits are increased, but the fabrication time increases and skilled welders are required
Solution Approach 1:
The groove is integrated directly into the pipe element sidewall through forming operations, merging the engagement feature with the pipe manufacturing process. This eliminates the separate welding step required for external rings, thereby reducing fabrication time and eliminating the need for skilled welders while maintaining reliable mechanical engagement for internal pressure and axial tensile loads.
Solution Approach 2:
The welding process is replaced with a mechanical forming process to create the groove in the pipe sidewall. This substitution eliminates the need for thermal welding operations, reducing fabrication time and skill requirements while achieving the same functional outcome of providing mechanical engagement surfaces for coupling keys.
3Ease of manufacture
If machined grooves are used in pipe sidewalls, then the coupling keys can mechanically engage, but the pipe element strength is reduced due to material removal
Solution Approach 1:
The groove is formed through plastic deformation or displacement of pipe wall material rather than material removal. This changes the manufacturing parameter from machining (subtractive) to forming (displacement), maintaining the pipe element's full cross-sectional area and tensile strength while creating the necessary groove geometry for coupling key engagement.
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 configuration enables pipe elements to realize a greater portion of their potential strength, improving axial tensile loading and internal pressure limits while eliminating the need for external welded rings, simplifying fabrication and reducing costs.
Implementation Method 1
The third sub-surface is oriented at an angle with respect to the longitudinal axis and sloping toward the second sub-surface... the at least one arcuate projection comprises a plurality of mating surfaces... a third mating surface oriented at an angle with respect to the longitudinal axis and contacting the third sub-surface
Data Source
Figure 1~2
Figure 3
Figure 3A
AI summary
A pipe element has a circumferential groove with a surface portion oriented at an angle with respect to its longitudinal axis. A surface portion of the groove adjacent to the angled surface portion is oriented perpendicular to the longitudinal axis. A mechanical coupling has projecting keys that engage the groove. The keys have mating surfaces that contact both the perpendicular and angled surface portions of the groove. When the pipe element and coupling are used in combination to form a pipe joint, axial load on the pipe, resisted by the mechanical coupling, is shared between the perpendicular and angled surface portions which results in a pipe joint that can withstand higher internal pressure than if the axial load were borne by the perpendicular surface portion alone.