Flexible Armoured Pipe With Metal Retaining Strip for Hydrolysis Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flexible pipes for marine applications, such as oil and gas transport, face challenges in cost-effectiveness, manufacturing flexibility, and resistance to hydrolysis, particularly due to the use of fibre-reinforced polymeric tapes for outer armouring layers, which are expensive and prone to degradation.
Innovation Solution
A flexible pipe design incorporating an elongate metallic strip as a retaining layer wound at a high angle around tensile armouring layers, providing radial protection without the need for expensive fibre-reinforced tapes, thus reducing production costs and improving durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fibre-reinforced polymeric tapes are used for outer armouring layers, then the pipe provides adequate radial protection, but the production cost increases and the material becomes prone to hydrolysis degradation
Solution Approach 1:
The patent replaces expensive fibre-reinforced polymeric tapes with cheaper metallic strips (such as stainless steel or aluminum) for the retaining layer. The metallic strips provide equivalent radial protection functionality while being more cost-effective and resistant to hydrolysis degradation in marine environments.
Solution Approach 2:
The patent changes the material parameter from polymeric composite to metal, and adjusts the winding angle parameter to at least 65 degrees. This parameter change enables the metallic retaining layer to provide adequate radial protection while improving resistance to hydrolysis and reducing production costs.
2Reliability
If fibre-reinforced polymeric tapes are used for outer armouring layers, then the pipe provides adequate radial protection, but the manufacturing flexibility is reduced
Solution Approach 1:
The patent substitutes metallic strips for fibre-reinforced polymeric tapes in the retaining layer, enabling more flexible manufacturing processes. Metallic strips can be more easily handled, wound, and installed during pipe assembly, thereby improving manufacturing flexibility while maintaining adequate radial protection.
Solution Approach 2:
By changing the material from polymeric tape to metal strip and increasing the winding angle to at least 65 degrees, the patent achieves a configuration that is both radially protective and more adaptable to different manufacturing methods and pipe configurations.
3Ease of manufacture
If metallic strips are used as retaining layers instead of fibre-reinforced tapes, then production cost is reduced and hydrolysis resistance is improved, but the weight of the pipe increases
Solution Approach 1:
The patent optimizes the metallic strip specifications including thickness, width, and winding angle (at least 65 degrees) to achieve the lightest possible configuration that still provides adequate radial protection. This parameter optimization minimizes the weight increase while maintaining cost-effectiveness and hydrolysis resistance.
Data Source
AI summary
The present invention relates to a flexible armoured pipe having a centre axis and including an internal pressure sheath and an outer sheath, where the radial distance between the internal pressure sheath and the outer sheath defines an annulus. The annulus includes at least one tensile armour layer surrounded by at least one retaining layer constituted by an elongate metallic strip wound around the at least one tensile armour with a winding angle of at least 65° in respect of the centre axis.