Reinforced Hydraulic Hose with Controlled Liner-Carcass Interlock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic hoses used in subsea systems are prone to failure due to the self-weight of the reinforcing carcass causing it to unwind or break under high hydrostatic pressure, as the steel carcass is not designed to retain pressure and the liner expands relative to the carcass, reducing friction and leading to separation.
Innovation Solution
A hose design with a tubular liner featuring high-infill portions and low-infill portions, where the liner protrudes into recesses on the carcass, providing enhanced engagement and support, and a manufacturing method using controlled pressure differentials and cooling to adjust the infill level, ensuring secure carcass-liner interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the steel carcass is used as a non-pressure retaining element, then the hose can withstand high hydrostatic pressure, but the liner expands relative to the carcass causing loss of friction and separation
Solution Approach 1:
The carcass surface is segmented with recesses that create discrete engagement zones. The liner material is segmented into protrusions that fit into these recesses, creating multiple localized friction points along the carcass-liner interface. This segmentation maintains reliable engagement even when overall friction decreases under pressure.
Solution Approach 2:
The solution combines the steel carcass (metallic material) with the thermoplastic liner (polymeric material) in a composite structure. The differential expansion between these two materials under pressure is managed by the geometric interlocking of recesses and protrusions, allowing each material to maintain its inherent properties while achieving reliable combined performance.
2Reliability
If the liner material is tightly engaged with the carcass, then the structural integrity is improved, but the processing and termination become more difficult
Solution Approach 1:
The engagement between liner and carcass is made non-uniform along the hose length. High-infill portions provide strong engagement for structural integrity in the main body, while low-infill portions provide easier processing and termination at specific locations. This local variation in engagement quality allows both contradictory requirements to be satisfied in different zones.
3Reliability
If the hose is deployed in deep water, then the utility and strength are improved, but the self-weight of the carcass exceeds the tensile strength causing unwinding or breakage
Solution Approach 1:
The solution transitions from relying solely on the carcass's axial tensile strength (one-dimensional property) to utilizing the radial dimension for engagement. The recesses and protrusions create a radial interlocking mechanism that transfers the carcass weight to the liner, allowing the hose to support deep water deployment loads without exceeding the carcass's tensile capacity.
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 enhances the hose's structural integrity by maintaining carcass-liner engagement, preventing separation and facilitating easier processing and termination, particularly in deep water applications.
Implementation Method 1
The liner is formed from a thermoplastic liner material which is extruded onto the outer surface of the hose carcass and cooled to control the flow and infill of the material
Implementation Method 2
selectively controlling the pressure differential between the inside and the outside of the liner to control the level of infill of the liner material into the recesses
Data Source
AI summary
The invention relates to forming a collapse resistant thermoplastic hydraulic high pressure hose for use with an umbilical, where a liner is applied to a reinforcing carcass in which the liner material is controlled to protrude into recesses on the carcass to improve the engagement of the liner and carcass and prevent relative slipping. The amount of liner material which protrudes into the recesses is controlled and may be reduced at selected portions along the hose, for example to facilitate easier removal of the carcass from the liner, for example for preparation of terminations.