Premium Connection Torque Shoulder Geometry for Staged Make-Up
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Solution Overview
Problem
In threaded pipe connections, a large standoff between torque shoulders during the make-up process can lead to galling of seal surfaces, compromising the seals, and requires significant turning to eliminate, which may cause damage and improper positioning.
Innovation Solution
The design incorporates pin and box torque shoulders with multiple surfaces, including top and bottom torque shoulder surfaces that contact each other in a specific sequence to control pin movement and prevent damage, featuring a nose and depression geometry that offsets the initial alignment to force the pin into a tighter connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large standoff between torque shoulders is maintained during make-up, then the pin seal surface and box seal surface remain in contact, but this requires significant turning to eliminate the standoff, which causes galling of seal surfaces and compromises the seals
Solution Approach 1:
The torque shoulder is divided into multiple surfaces (first torque shoulder surface and second torque shoulder surface) that contact the box in a specific sequence. This segmentation allows the standoff to be eliminated in controlled stages rather than all at once, preventing galling while maintaining seal contact
Solution Approach 2:
The pin is designed with a nose and depression geometry that offsets initial alignment, forcing the pin into a tighter connection before full makeup. This preliminary action ensures proper positioning and reduces the risk of galling during the make-up process
2Ease of operation
If significant turning is applied to eliminate the standoff, then the torque shoulders eventually contact, but this excessive turning causes galling and damage to seal surfaces
Solution Approach 1:
The torque shoulder contact is segmented into multiple surfaces that engage in sequence. This allows the make-up process to proceed with controlled, staged contact rather than requiring excessive single-stage turning, thereby completing the operation without damaging the seal surfaces
Solution Approach 2:
The torque shoulder design allows dynamic adjustment of contact points during the make-up process. As the pin is threaded into the box, different torque shoulder surfaces engage at different stages, providing a progressive contact mechanism that prevents sudden excessive forces
3Stability of the object's composition
If the pin is forced into a tighter connection with offset geometry, then movement and deformation of the pin are reduced, but this requires more complex torque shoulder geometry with multiple surfaces
Solution Approach 1:
The pin features asymmetric nose and depression geometry that offsets the initial alignment. This asymmetric design forces the pin into a tighter, more stable connection during make-up, while the corresponding asymmetric torque shoulder surfaces provide controlled contact points
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A~2B
AI summary
A threaded tubular connection includes a pin having external threads, a pin seal surface, and a pin torque shoulder at a free end and a box for receiving the pin, a box seal surface for contacting the pin seal surface and a box torque shoulder for contacting the pin torque shoulder. The pin torque shoulder defines a receptacle. The box torque shoulder defines a nose.