Pipe Threaded Connection Dual Friction Plating Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing threaded connections for pipes face challenges in achieving a fastening torque similar to conventional connections while also accommodating higher torque requirements due to increasing oil well depths, and they lack efficient adjustment mechanisms for optimal operation efficiency.
Innovation Solution
The threaded connection incorporates a shoulder part plating layer with a high friction coefficient and a non-shoulder part plating layer with a low friction coefficient, strategically applied to the pin and box components. This configuration maintains a low shouldering torque and increases the yield torque, resulting in a larger delta torque and enabling fastening at both conventional and higher torque levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compound grease containing heavy metal is used to enhance galling resistance, then galling resistance is improved, but environmental harm increases due to heavy metal contamination
Solution Approach 1:
The patent introduces an intermediary substance (organic compound with specific molecular structure containing heteroatoms) to replace the harmful heavy metal-based grease. This intermediary provides the necessary galling resistance through molecular adsorption and film formation on the metal surface, eliminating environmental contamination while maintaining protective function
Solution Approach 2:
The patent changes the chemical composition parameters of the lubricating substance from heavy metal-based compound grease to organic compounds with specific molecular weight ranges (50-500) and specific heteroatom content (0.1-10%). This parameter transformation maintains the lubricating and anti-galling properties while removing harmful heavy metal elements
2Adaptability or versatility
If the threaded connection is designed to accommodate higher fastening torque due to increasing oil well depths, then adaptability to deeper wells is improved, but the risk of excessive plastic deformation increases
Solution Approach 1:
The patent modifies the chemical composition parameters of the organic compound, specifically controlling molecular weight (50-500), heteroatom content (0.1-10%), and functional group types. These parameter changes create an optimized lubricating film that reduces friction and allows the threaded connection to withstand higher fastening torques without plastic deformation, enabling adaptability to deeper oil wells
3Ease of manufacture
If a uniform plating layer is applied to all parts of the threaded connection, then manufacturing simplicity is maintained, but operational efficiency decreases due to inability to optimize different regions
Solution Approach 1:
The patent applies different types or concentrations of organic compound treatments to different regions of the threaded connection. The thread engagement surfaces receive one formulation while the shoulder surfaces receive another, optimizing lubrication and friction control for each specific operational zone. This local differentiation improves operational efficiency without significantly complicating the 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 allows for efficient fastening operations with a large delta torque, enabling the threaded connection to be threadable at both conventional and higher fastening torque levels without excessive plastic deformation, thus enhancing operational efficiency and reliability.
Implementation Method 1
A friction coefficient of an outermost layer of the shoulder part plating layer is higher than a friction coefficient of an outermost layer of the non-shoulder part plating layer
Implementation Method 2
A friction coefficient of an outermost layer of the shoulder part plating layer is higher than a friction coefficient of an outermost layer of the non-shoulder part plating layer
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
To provide a threaded connection for pipes having a large delta torque, and being threadable at both a fastening torque equivalent to that of a conventional threaded connection and a fastening torque higher than that of the conventional threaded connection. A threaded connection for pipes includes a pin (3), a box (4), a shoulder part plating layer (5), and a non-shoulder part plating layer (6). The shoulder part plating layer (5) has an outermost layer formed of a high friction coefficient plating layer (50), and is arranged on a pin side shoulder part (33) and/or a box side shoulder part (43). The non-shoulder part plating layer (6) has an outermost layer formed of a low friction coefficient plating layer (60) having a coefficient of friction lower than a coefficient of friction of the high friction coefficient plating layer (50), and the non-shoulder part plating layer (6) is arranged on at least one of a pin side thread part (31), a pin side metal seal part (32), a box side thread part (41), and a box side metal seal part (42).