Wedging Groove Pipe Joint for Higher Pressure Load Sharing
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Solution Overview
Problem
Existing mechanical couplings for joining pipe elements are limited in withstanding loads such as internal pressure and axial tensile forces, as they do not fully realize the potential strength of the pipe, and require external welded rings which add cost and complexity to fabrication.
Innovation Solution
The design of pipe elements with specific angled grooves and arcuate projections that engage with adjustable attachment members, allowing for improved mechanical engagement without the need for external welded rings, enhancing the pipe's strength and pressure capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional circumferential grooves are used in pipe elements, then mechanical coupling engagement is achieved, but the joint cannot withstand loads up to the full tensile strength of the pipe
Solution Approach 1:
The groove geometry parameters are changed from traditional arcuate shapes to specific angled surfaces (first surface at 80-90 degrees, second surface at 40-70 degrees, third surface at 0-10 degrees relative to longitudinal axis). These parameter changes enable the groove to engage the coupling key more effectively, distributing loads across multiple surfaces and allowing the joint to withstand loads up to the full tensile strength of the pipe.
2Strength
If external welded rings are added to pipe elements, then mechanical engagement strength is improved, but fabrication cost and complexity increase
Solution Approach 1:
The external welded rings are extracted from the design. Instead of adding separate reinforcement components, the groove itself is designed with optimized geometry that provides the necessary mechanical engagement strength directly in the pipe element, eliminating the need for additional welded rings and their associated fabrication complexity.
Solution Approach 2:
The groove design merges the functions of mechanical engagement and load distribution into a single integrated feature. The multi-surface groove geometry combines the engagement function with the reinforcement function that previously required separate welded rings, simplifying the overall structure.
3Stress or pressure
If external welded rings are used to enhance joint strength, then pressure capacity increases, but welding requirements add cost and time
Solution Approach 1:
The welding process is extracted from the fabrication sequence. The groove geometry is designed to provide full pressure capacity without requiring welding of external rings. The groove can be formed by conventional machining or forming processes, significantly simplifying fabrication and eliminating skilled welding requirements.
4Strength
If traditional groove designs are used, then pipe element strength is not fully realized, but simpler groove shapes are easier to manufacture
Solution Approach 1:
Specific parameter ranges are defined for the groove surfaces to optimize strength while maintaining manufacturability. The first surface angle (80-90 degrees), second surface angle (40-70 degrees), and third surface angle (0-10 degrees) are carefully selected to maximize load distribution and engagement effectiveness. These parameters can be achieved with conventional machining tolerances.
Solution Approach 2:
Different regions of the groove are given different surface orientations optimized for their specific functions. The first surface (80-90 degrees) handles axial loads, the second surface (40-70 degrees) provides lateral engagement, and the third surface (0-10 degrees) ensures proper key seating. This local optimization of geometry achieves high strength utilization with standard manufacturing capabilities.
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 enables pipe elements to achieve a greater percentage of their potential strength, improving the joint's ability to withstand loads and increasing internal pressure performance without the need for external welded rings, thus simplifying and reducing the cost of fabrication.
Implementation Method 1
the first groove is defined by a first plurality of sub-surfaces of the outer surface including: a first sub-surface oriented at an angle with respect to the longitudinal axis and facing away from the first end; a second sub-surface oriented at an angle with respect to the longitudinal axis, the second sub-surface being in spaced relation away from and facing toward the first sub-surface
Data Source
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.