Threaded Pipe Connection With Reduced End-Thread Interference
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Solution Overview
Problem
Existing threaded pipe connections in the natural gas and oil extraction industry face issues with radial inward deformation of pipe terminal ends, which can lead to operational challenges and increased costs due to potential sticking and damage during quality checks.
Innovation Solution
The proposed threaded pipe connection features a tubular coupling with first and second female threaded zones and pipes with male threaded zones and shoulder surfaces. The female threaded zones are designed with a first portion of constant thread height and a second portion with reduced thread height, reducing radial interference and deformation at the pipe terminal ends.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional threaded connections with constant thread height are used, then strong engagement and connection strength are achieved, but radial inward deformation of pipe terminal ends occurs causing drift passage problems
Solution Approach 1:
The threaded zone is segmented into two distinct portions: a first portion with constant thread height for strong engagement, and a second portion with reduced thread height near the terminal end to minimize radial interference and deformation. This segmentation allows the connection to simultaneously achieve both strong engagement and drift passage capability.
Solution Approach 2:
Different regions of the threaded zone are given different thread heights tailored to their specific functional requirements. The first portion has full thread height for maximum strength, while the second portion has reduced thread height to prevent radial inward deformation at the terminal end, allowing the drift to pass through during quality checks.
2Strength
If radial interference is increased to improve connection strength, then engagement is enhanced, but terminal end deformation increases causing operational problems
Solution Approach 1:
The threaded zone is divided into two portions with different thread heights. The first portion provides strong engagement with full radial interference, while the second portion near the terminal end has reduced thread height to minimize radial interference and prevent terminal end deformation.
Solution Approach 2:
The thread height is locally optimized: full height in the first portion for strong engagement, and reduced height in the second portion at the terminal end to maintain shape stability and prevent inward deformation.
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 reduces or avoids radial inward deformation of pipe terminal ends, enhancing the connection's ability to accommodate a drift during quality checks and reducing operational costs associated with potential damage and repair.
Implementation Method 1
the crest of one of the male and female threads radially interferes with the root of the other of the male and female threads
Implementation Method 2
the threaded zones of the pipes engage the threaded zones of the tubular coupling
Implementation Method 3
the shoulder surfaces of the first and second pipes abut
Data Source
AI summary
The present invention relates to a threaded pipe connection. A threaded pipe connection comprising a tubular coupling with first and second female threaded zones formed in opposing sections; and first and second pipes, each comprising a male threaded zone and a shoulder surface at its terminal end, wherein each female threaded zone includes a female thread that tapers radially within the female threaded zone from a maximum diameter at the outer end of the female threaded zone, wherein each male threaded zone includes a male thread that tapers radially so as to reduce in diameter towards the terminal end of the pipe, wherein the threaded pipe connection is configured to enable the first and second pipes to be engaged with the tubular coupling in a made-up configuration in which: the shoulder surfaces of the first and second pipes abut; the entire male threaded zone of the first pipe engages the entire first female threaded zone; the entire male threaded zone of the second pipe engages the entire second female threaded zone; and for each of the first and second female threaded zones. The crest of one of the male and female threads radially interferes with the root of the other of the male and female threads in a first portion of the female threaded zone and does not interfere or interferes by a smaller amount in a second portion of the female threaded zone; the second portion is located at the inner end of the female threaded zone.