Flexible Pipe End Piece With Self-Energizing Composite Seal

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Solution Overview

Problem

Flexible fluid transport pipes used in deep water oil and gas industries face issues such as fluid flow disturbances, fatigue corrosion, and leakage due to the presence of internal carcasses and sealing members, which can lead to operational safety risks and environmental harm.

Innovation Solution

The development of an end piece for flexible fluid transport pipes featuring a composite reinforcement structure with a sealing member having a conical front surface and a thick, deformable polymer sealing member that self-energizes under pressure to ensure a tight connection, reducing radial stresses and enhancing sealing effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing element is placed between the arch and the composite structure, then sealing function is provided, but the risk of leakage increases due to assembly errors and mechanical stresses

Engineering Contradiction:
Improvesealing reliabilityVSAvoidfitting assembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing function is extracted from a separate sealing element and integrated directly into the composite reinforcement structure through an interference fit with the arch. The composite structure itself becomes the sealing component, eliminating the need for additional sealing elements and reducing assembly complexity while improving sealing reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing function is merged with the structural function of the composite reinforcement structure. The interference fit between the arch and the composite structure serves both structural support and sealing purposes simultaneously, reducing the number of components and potential failure points.

Inventive Principle:
Principle #5Merging (Combining)

2Strength

If an internal reinforcement is placed inside the pipe casing, then pipe crushing is prevented, but fluid flow disturbances and fatigue corrosion occur

Engineering Contradiction:
Improveresistance to radial crushing forcesVSAvoidfluid flow disturbances and fatigue corrosion
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

A composite reinforcement structure is used instead of traditional metal spiral reinforcement. The composite material provides equivalent or superior crush resistance while being smoother on the internal surface, reducing fluid flow disturbances and susceptibility to fatigue corrosion.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The composite reinforcement structure can be designed with porous or textured surfaces that reduce fluid turbulence and improve flow characteristics while maintaining structural integrity against radial crushing forces.

Inventive Principle:
Principle #31Porous materials

3Length of moving object

If the flexible pipeline is made very long for deep water applications, then deep water connectivity is achieved, but the risk of leakage and structural failure increases

Engineering Contradiction:
Improvepipeline lengthVSAvoidconnection reliability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The interference fit connection between the arch and composite structure creates a self-energizing sealing mechanism where the operational loads and pressure differential enhance the sealing contact pressure, making the connection more reliable over time and reducing leakage risk in long deep water pipelines.

Inventive Principle:
Principle #25Self-service

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 solution provides a reliable, self-energizing sealing mechanism that maintains high contact pressure even under varying conditions, ensuring a tight connection and reducing the risk of leakage, thus enhancing operational safety and environmental protection.

Implementation Method 1

a thick, deformable polymer sealing member that self-energizes under pressure to ensure a tight connection

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a conical front surface and a thick, deformable polymer sealing member that self-energizes under pressure

Methodology Applied
Scientific EffectStress distribution: Geometry

Data Source

PatentEP3692295B1Attachment end piece for a flexible pipe, associated flexible pipe and associated method
Publication Date: 2021.11.03 TECH N POWER
  • EP3692295B1 patent drawingFigure 1
  • EP3692295B1 patent drawingFigure 2~3
  • EP3692295B1 patent drawingFigure 4~7

AI summary

The end piece comprises: - an end dome (60); - an end region (56) of a composite reinforcement structure (22); - a holding member (92) suitable for holding the end region (56) of the composite reinforcement structure (22) attached against the end dome (60); and - a sealing member (90). The sealing member (90) projects radially around at the end region (56) of the composite reinforcement structure (22), while being connected to the end region (56) of the composite reinforcement structure (22). The sealing member (90) has a front surface (96) which is not perpendicular to a central axis. The front surface (96) engages with a complementary seat (94) on the end dome (60), the sealing member (90) having a rear surface (100) applied against a stop (110) of the holding member (92).