Wedging Groove Pipe Element for Higher-Pressure Mechanical Joints
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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, and current solutions involving external welded rings are costly and require skilled labor.
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 external welded rings are used to improve mechanical engagement, then the pipe strength and pressure capacity increase, but the manufacturing complexity and cost increase due to welding requirements
Solution Approach 1:
The groove is integrated directly into the pipe element sidewall rather than being a separate external ring, combining the groove function with the pipe structure itself. This eliminates the need for separate welded rings while maintaining the mechanical engagement capability
Solution Approach 2:
The groove formation process is extracted from the pipe manufacturing process itself through rolling operations, allowing the groove to be created as part of the pipe forming without requiring separate welding operations
2Reliability
If external welded rings are used to enhance mechanical engagement, then the internal pressure performance improves, but the fabrication time and labor skill requirements increase
Solution Approach 1:
The groove is formed during the pipe manufacturing process itself through rolling operations, preparing the mechanical engagement feature in advance before the pipe is installed. This eliminates the need for separate field welding operations that would consume additional time and require skilled labor
3Ease of manufacture
If traditional arcuate grooves are used, then the manufacturing process is simple, but the joint cannot withstand full tensile strength of the pipe under load
Solution Approach 1:
The groove cross-section is designed with specific angular surfaces (first surface at 80-90 degrees, second surface at 40-70 degrees, third surface at 0-25 degrees) that create optimized contact areas with the coupling keys. This localized geometric optimization enhances the mechanical engagement and load distribution without complicating the overall manufacturing process
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 realize a greater portion of their potential strength, increasing internal pressure and axial tensile loading limits while simplifying fabrication and reducing costs by eliminating the need for external welded rings.
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; a third sub-surface contiguous with the first sub-surface, the third sub-surface oriented at an angle with respect to the longitudinal axis and sloping toward the second 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.