Flexible Pipe End Fitting Seal Using a Tightened Polymeric Sheath
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing end fittings for flexible, unbonded fluid pipes used in hydraulic fracturing require complex metal-to-metal sealing methods, which are cumbersome, lengthen the fitting, and increase weight due to the need for multiple elements and precise surface finishes.
Innovation Solution
An end fitting design featuring a cannula and annular protrusions on the internal surface of the end vault, allowing the internal polymeric sheath to be circumferentially tightened between the protrusions and the cannula, reducing the number of elements and weight while maintaining fluid tightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal-to-metal sealing method is used with inner and outer metallic layers, then fluid tightness is achieved, but the end fitting length and weight increase due to multiple elements and precise surface finish requirements
Solution Approach 1:
The invention extracts the sealing function from the complex metal-to-metal sealing system and relocates it to the polymeric sheath itself. The sheath is plastically deformed to create a seal against the monocone, eliminating the need for multiple metallic sealing layers and reducing overall end fitting weight while maintaining fluid tightness.
Solution Approach 2:
The invention changes the material parameter from metallic sealing surfaces to polymeric material that can be plastically deformed. By plastically deforming the polymeric sheath, a reliable seal is created against the monocone without requiring precise metal-to-metal surface finishes, thereby reducing weight and simplifying the sealing mechanism.
2Reliability
If metal-to-metal sealing method is used with inner and outer metallic layers, then fluid tightness is achieved, but the number of elements increases making the assembly more complex
Solution Approach 1:
The invention merges the sealing function with the polymeric sheath itself, combining structural support and sealing functions into a single component. This eliminates the need for separate inner metallic layer, outer metallic layer, and multiple sealing elements, significantly reducing end fitting complexity while maintaining fluid tightness.
Solution Approach 2:
The invention extracts the sealing function from the complex metallic sealing system and relocates it to the polymeric sheath. This simplification reduces the number of elements from multiple metallic layers to a single polymeric sheath that seals against the monocone, making the assembly less complex.
3Reliability
If crimping operation is made from the rear side of the vault, then sealing is achieved, but interference with armors occurs requiring them to be laid back which lengthens the end fitting
Solution Approach 1:
The invention inverts the crimping operation direction by performing it from the front side of the vault instead of the rear side. The monocone is pressed downward and plastically deformed by pushing it forward on a slope machined in the vault, allowing armors to remain in their normal position without being laid back, thereby reducing end fitting length.
4Reliability
If metal to metal seal is used, then fluid tightness is achieved, but precise surface finish is required increasing manufacturing difficulty
Solution Approach 1:
The invention changes the material parameter from metallic sealing surfaces requiring precise finishes to polymeric material that can be plastically deformed. By plastically deforming the polymeric sheath, a reliable seal is created against the monocone without requiring precise surface finishes, significantly easing manufacturing.
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 design simplifies the sealing process, reduces the length and weight of the end fitting, and provides effective fluid tightness with fewer components, enhancing ease of assembly and operational efficiency.
Implementation Method 1
The at least one part of the front region of the internal polymeric sheath is plastically deformed by the protrusion
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An end fitting (14) of a flexible pipe (14) for conveying a fluid comprising: - an end vault (42) and an outer cover (44) fixed around the end vault (42), - at least a front region (36) of an internal polymeric sheath (18), - at least end sections (40) of at least one tensile armor layer (24, 25) arranged around the internal polymeric sheath (18), - a front sealing assembly (54) arranged around the front region (36) of the internal polymeric sheath (18). The front sealing assembly (54) comprises a cannula (64) supporting at least one part of the front region (36) of the internal polymeric sheath (18) and an annular protrusion (66) arranged on an internal surface (48) of the end vault (42). the front region (36) of the internal polymeric sheath (18) is circumferentially tightened between the at least one protrusion (66) and the cannula (64).