Slotted Polymer Pipe Lining for Depressurization Gas Release
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Solution Overview
Problem
Subsea and onshore pipelines face the challenge of buckling or collapse of the protective lining during sudden depressurization, due to gas permeation and accumulation under the lining, which compromises the integrity of the pipeline and increases operational costs.
Innovation Solution
The pipeline incorporates an annular polymer lining with a plurality of slots that extend from the inner to the outer face of the lining. These slots allow gas to be discharged into the tube during depressurization, minimizing pressure differentials and preventing buckling, while their design minimizes dirt penetration and promotes efficient gas discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a polymer protective lining is used instead of alloy steel lining, then manufacturing cost is reduced, but the lining becomes permeable to gases allowing gas accumulation under the lining
Solution Approach 1:
The patent intentionally introduces controlled porosity through slots in the polymer lining to manage gas accumulation. These slots allow gas to escape from the interstitial space between the lining and steel tube, preventing over-pressurization while maintaining the cost advantages of polymer material.
Solution Approach 2:
The patent applies local quality by creating specific zones of permeability through slots at predetermined locations on the lining, while the rest of the lining maintains its protective function. This localized gas discharge mechanism addresses the gas tightness issue without compromising the overall integrity or requiring expensive alternative materials.
2Strength
If the polymer lining thickness is increased to improve corrosion protection, then protection effectiveness is improved, but gas accumulation pressure increases during depressurization events
Solution Approach 1:
The patent extracts the harmful gas accumulation from the system by providing dedicated escape paths through the slots. This allows the lining thickness to be optimized for corrosion protection without being constrained by gas pressure build-up, as the gas can escape through the slots rather than increasing pressure against the lining.
3Productivity
If slots are made larger or more numerous to improve gas discharge, then gas discharge efficiency is improved, but dirt and debris penetration into the slots increases
Solution Approach 1:
The patent applies dynamics by making the slots movable rather than fixed. The slots can open wider when gas pressure builds up to facilitate rapid discharge, then close or reduce opening when pressure equalizes to prevent dirt and debris from entering. This dynamic behavior optimizes both gas discharge efficiency and contamination prevention.
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 slot design effectively discharges accumulated gas during depressurization, preventing buckling and maintaining the integrity of the protective lining, thus reducing operational risks and costs associated with pipeline maintenance and corrosion protection.
Implementation Method 1
gas tends to penetrate the polymer material and to pass through the protective lining in order to lodge in the interstitial space between the lining and the inner wall of the steel tube
Implementation Method 2
A pressure differential is then created with an over-pressurization on the side of the interstitial space, with a risk of occurrence of local buckling or collapse of the protective lining
Data Source
AI summary
A pipeline for the transport of fluids includes a steel tube intended to receive a flow of fluids to be transported, and an annular lining for protection against corrosion and/or abrasion made of polymer material, and inserted inside the tube. The lining includes a plurality of slots which extend in the direction of their length parallel to a longitudinal axis of the tube and which pass all the way from an inner face to an outer face of the lining, each slot being open on the side of the inner face of the lining prior to the insertion of the lining into the tube, and at least partially closed between the inner face and the outer face of the lining along of its depth once the lining is inserted into the tube.