Angled Threaded Pipe Connection for Compression-Resistant Sealing
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Solution Overview
Problem
Threaded connections in pipes, particularly those used in oil and gas pipelines, are prone to failure under tensile and compressive forces, leading to damage at the thread and seal interfaces, which can result in leaks and structural weaknesses.
Innovation Solution
The design features a threaded connection with angled pin and box threads, where the roots and crests of adjacent threads are aligned to deflect axial compressive forces radially outward, reducing stress on the threads and enhancing the sealing surfaces, allowing for increased torque capacity and resistance to compressive forces without compromising the seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional threaded connections are used, then the connection can be made with standard threading, but the connection is prone to failure under compressive forces and tensile forces
Solution Approach 1:
The patent applies asymmetry by creating an asymmetric thread profile where the root of each thread is offset radially outwardly relative to the crest. This asymmetric geometry causes the load flanks of adjacent threads to contact and interfere with each other, creating a mechanical interlock that resists compressive forces. The asymmetric design transforms the traditional symmetric thread into a compression-resistant structure where the load is distributed across multiple thread flanks rather than concentrated at a single point.
Solution Approach 2:
The patent changes the geometric parameters of the thread profile by offsetting the root position radially outwardly from the crest position. This parameter change creates a tapered thread form where the root diameter is larger than what would be expected in a conventional thread. The modified parameters enable the thread flanks to engage more effectively under compressive loading, transforming the thread geometry to withstand higher compressive forces without failure.
2Strength
If higher torque is applied to tighten the connection, then the connection becomes more secure, but the sealing surfaces may fail or become damaged
Solution Approach 1:
The patent segments the torque transmission function across multiple thread flanks rather than concentrating it at a single interface. By creating a multi-flank engagement where load flanks of adjacent threads contact sequentially, the torque is distributed across several contact points. This segmentation prevents excessive stress concentration at any single sealing surface, allowing higher overall torque application without damaging the seal.
Solution Approach 2:
The asymmetric thread geometry provides beforehand cushioning by creating a progressive engagement mechanism. As torque is applied, the load flanks engage in a controlled sequence, with each flank bearing a portion of the load. This progressive load distribution acts as a cushioning mechanism that prevents sudden stress spikes from reaching the sealing surfaces, protecting them from damage even under high torque conditions.
3Strength
If the thread profile is modified to increase compression resistance, then the connection can withstand higher compressive forces, but the manufacturing complexity increases
Solution Approach 1:
The patent modifies thread parameters (root offset, flank angles, pitch) to achieve compression resistance. While this changes the geometry, the modification follows a systematic pattern that can be implemented using standard threading equipment with adjusted parameters. The consistent radial offset applied to each thread root creates a repeatable manufacturing process that, while requiring precision, does not fundamentally change the manufacturing approach.
Solution Approach 2:
The patent applies local quality by modifying only specific critical features of the thread profile (the root position and load flank geometry) while maintaining standard thread characteristics in other areas. This localized modification focuses the manufacturing complexity only where needed to achieve compression resistance, rather than requiring complete redesign of the entire threading process. The crests and basic thread form remain relatively standard, simplifying manufacturing.
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 design effectively reduces the risk of failure under compressive forces, maintains the integrity of sealing surfaces, and allows for higher torque without increasing interference, thereby enhancing the durability and reliability of threaded connections in pipelines.
Implementation Method 1
Deflection of axial compressive forces radially outwardly can operate to help protect and save sealing surfaces from failure
Data Source
AI summary
A threaded connection having a straight central axis, where the pin threads and the box threads are arranged such that when the connection is fully made up, the pin roots and box crests come into at least partial interference substantially in line with a pin root taper plane and a box crest taper plane, and wherein the angles of the pin root taper plane and box crest taper plane allow for reduction of axial compressive forces on the plurality of pin threads and plurality of box threads along the central axis.