Tubular Joint Sealing Structure for End Face Separation Under Bending
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Solution Overview
Problem
Tubular joints used in subsea oil and gas applications face sealing integrity issues under high bending loads, where slight separation of end faces can lead to loss of fluid-tight seal.
Innovation Solution
A tubular joint design incorporating an annular metallic body with spring-energized polymeric seal members, which are prestressed upon clamping, to maintain sealing integrity by forming both primary and secondary seals against internal and external fluid pressures, even when end faces are slightly separated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metallic seal ring with tapered sealing surfaces is used to form a primary seal between tubular members, then sealing effectiveness against internal fluid pressure is improved, but sealing integrity is lost when end faces are slightly separated under high bending load
Solution Approach 1:
The sealing system is divided into two independent sealing mechanisms: a primary seal using a metallic seal ring with tapered sealing surfaces, and a secondary seal using elastomeric annular seal members. This segmentation allows each seal to perform its specific function - the primary seal handles normal operating conditions while the secondary seal provides backup when end faces separate, thereby maintaining overall sealing integrity without requiring a single complex seal design
Solution Approach 2:
The elastomeric annular seal members are positioned to provide beforehand cushioning against the possibility of end face separation. These secondary seals are pre-installed and ready to activate when the primary seal becomes compromised due to bending loads causing end face separation, thus preventing sealing integrity loss before it occurs
2Reliability
If elastomeric annular seal members are added as secondary seals between the seal ring and tubular members, then sealing integrity under damaged primary seal conditions is improved, but device complexity increases
Solution Approach 1:
The sealing system is divided into two independent sealing mechanisms: a primary seal using a metallic seal ring with tapered sealing surfaces, and a secondary seal using elastomeric annular seal members. This segmentation allows each seal to perform its specific function - the primary seal handles normal operating conditions while the secondary seal provides backup when end faces separate, thereby maintaining overall sealing integrity without requiring a single complex seal design
Solution Approach 2:
The elastomeric material used for the annular seal members provides homogeneous sealing properties around the entire circumference of the joint. This uniform material composition ensures consistent sealing performance throughout the seal, simplifying the design compared to using multiple different components or materials to achieve the same backup sealing function
3Reliability
If the tubular joint is designed to maintain sealing under bending loads, then reliability under high bending load is improved, but the seal structure becomes more complex
Solution Approach 1:
The elastomeric annular seal members are positioned to provide beforehand cushioning against the possibility of end face separation. These secondary seals are pre-installed and ready to activate when the primary seal becomes compromised due to bending loads causing end face separation, thus preventing sealing integrity loss before it occurs
Solution Approach 2:
The sealing system utilizes parameter changes by employing materials with different physical properties - the metallic seal ring provides rigid sealing under normal conditions, while the elastomeric annular seal members provide flexible sealing when end faces separate under bending loads. This change in material parameter (rigidity to flexibility) allows the seal to adapt to different loading conditions without structural complexity
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
The design ensures the tubular joint maintains a fluid-tight seal under bending loads by utilizing the flexibility and prestressing of the spring-energized polymeric seal members to maintain contact with radially extending sealing surfaces, enhancing the reliability and stability of the seal.
Implementation Method 1
spring-energized polymeric seal members which are configured to be prestressed upon clamping of the tubular members to each other
Implementation Method 2
the spring-energized polymeric seal members are configured to be prestressed upon clamping of the tubular members to each other
Data Source
Figure 1~3
Figure 4~6
AI summary
A tubular joint comprising first and second tubular members (10, 20), an annular sealing element (40) positioned between the tubular members and a clamping device (30) for clamping the tubular members to each other with an end face of the first tubular member in contact with an end face of the second tubular member. The sealing element comprises an annular metallic body (41). Two sealing surfaces (46a, 46b) on the metallic body are designed to mate with tapered sealing surfaces (16, 26) on the tubular members. A first spring-energized polymeric seal member (47a) is mounted to the metallic body and configured to be in sealing contact with a radially extending sealing surface (17) on the first tubular member. A second spring-energized polymeric seal member (47b) is mounted to the metallic body and configured to be in sealing contact with a radially extending sealing surface (27) on the second tubular member. Said seal members (47a, 47b) are prestressed upon clamping of the tubular members to each other.