Ultrasonic Surface Wave Evaluation for Pipe Thread Coupling Shoulder Contact
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Solution Overview
Problem
Conventional methods for evaluating the fastening state of threaded joints in OCTG (Oil Country Tubular Goods) are inaccurate and labor-intensive, as they rely on monitoring torque changes during fastening, which can be influenced by factors other than tight contact, and require manual insertion of clearance gauges, making it difficult to assess the contact between shoulder parts effectively.
Innovation Solution
An ultrasonic surface wave evaluation method that transmits and receives waves through the shoulder parts of a threaded joint to determine the contact interfacial pressure, using probes with convex contact surfaces and elastic members to stabilize their position, allowing for accurate assessment of the fastening state without continuous monitoring during the fastening process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If torque monitoring is used to evaluate fastening state, then the evaluation can be performed during fastening process, but the measurement accuracy is insufficient because torque changes can be influenced by factors other than tight contact
Solution Approach 1:
The patent replaces the mechanical torque monitoring system with an ultrasonic wave-based detection system. Ultrasonic surface waves are transmitted through the shoulder parts of the threaded joint, and the transmitted wave intensity is measured to evaluate the contact state. This substitution eliminates the influence of friction and other mechanical factors that affect torque measurements, providing more accurate assessment of the actual contact between shoulder parts.
Solution Approach 2:
The patent changes the measurement parameter from torque (which is influenced by multiple factors including friction) to ultrasonic wave intensity (which directly reflects contact conditions). By measuring the intensity of ultrasonic waves transmitted through the shoulder parts, the system directly correlates wave intensity with contact interfacial pressure, providing a more precise indicator of fastening state.
2Measurement precision
If clearance gauge insertion method is used to evaluate shoulder part contact, then direct measurement of contact is possible, but the operation becomes labor-intensive and time-consuming
Solution Approach 1:
The patent replaces the manual mechanical clearance gauge insertion method with an ultrasonic wave-based detection system. The ultrasonic surface waves can penetrate through the shoulder parts and their transmitted intensity provides direct information about contact conditions without requiring physical insertion of gauges or manual measurement operations.
Solution Approach 2:
The ultrasonic detection system enables automatic evaluation of the fastening state. The transmitted wave intensity is directly measured and can be automatically correlated with contact quality, eliminating the need for manual insertion of clearance gauges and manual assessment by operators.
3Reliability
If torque monitoring is used to evaluate fastening state, then continuous monitoring during fastening is possible, but the reliability is insufficient because other factors can generate great torque
Solution Approach 1:
The patent replaces the torque-based mechanical evaluation system with an ultrasonic wave transmission system. Since ultrasonic waves directly interact with the contact interface between shoulder parts, the transmitted wave intensity provides reliable information about actual contact conditions without being influenced by friction, thread engagement, or other factors that affect torque measurements.
Solution Approach 2:
The patent changes the evaluation parameter from torque (indirect and influenced by multiple factors) to ultrasonic wave intensity (direct indicator of contact conditions). This parameter change improves reliability by establishing a direct correlation between wave intensity and contact interfacial pressure, eliminating the ambiguity inherent in torque-based evaluation.
4Measurement precision
If manual clearance gauge insertion is used to evaluate fastening state, then detailed contact assessment is possible, but the operation requires significant manual intervention
Solution Approach 1:
The patent replaces the manual mechanical clearance gauge insertion process with an ultrasonic wave-based detection system. The ultrasonic surface waves are transmitted through the shoulder parts and the transmitted intensity is automatically measured, providing contact state information without requiring manual insertion operations or complex gauge handling procedures.
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 method provides a simple, accurate, and efficient way to evaluate the fastening state of threaded joints by correlating ultrasonic wave intensity with contact interfacial pressure, enabling precise determination of shoulder part contact and reducing the need for manual intervention, thus improving the reliability and speed of the evaluation process.
Implementation Method 1
transmitting ultrasonic surface waves from the internal surface of either one of the pin and the box toward the internal surface of the other one of the pin and the box through the shoulder parts of the pin and the box
Implementation Method 2
on the basis of the transmitted wave intensity or the reflected wave intensity thereof, determining whether or not the fastening state of the threaded joint is satisfactory
Data Source
Figure 1
Figure 2~3B
Figure 4A~4C
AI summary
The present invention provides a method which allows simply, easily and accurately evaluating the fastening state of shoulder parts of a threaded joint for use as a joint of pipes or tubes, such as OCTG, during fastening or after fastening. The fastening state evaluation method for a threaded joint 100 of pipes or tubes according to the present invention is characterized in that it transmits ultrasonic surface waves from the internal surface of either one of the pin 1 and the box 2 toward the internal surface of the other one of the pin 1 and the box 2 through the shoulder parts 13, 23 of the pin 1 and the box 2, and on the basis of the transmitted wave intensity or the reflected wave intensity thereof, determines whether or not the fastening state of the threaded joint 100 is satisfactory.