Field Joint Coating Material for Fast-Curing Pipeline Insulation
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Solution Overview
Problem
Current field joint coating systems for pipelines fail to achieve rapid application and solidification while maintaining compatibility and insulation properties, especially in deep water applications, where they are required to withstand high temperatures and hydrolysis resistance, and often require complex equipment and high viscosity materials.
Innovation Solution
A process involving abrading the steel pipe surfaces, applying an epoxy primer and maleic anhydride grafted polyethylene or polypropylene resins, and injecting a fast-curable olefin formulation based on norbornene-type cycloolefin monomers with a catalytic system for Ring Opening Metathesis Polymerization, which allows for quick curing and chemical welding with the parent coating, reducing cycle time and ensuring water tightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high temperature conditions are used to reduce melted viscosity for polypropylene injection, then the viscosity of the thermoplastic polymer is reduced, but the time needed to cool down and solidify the field joint increases
Solution Approach 1:
The invention changes the chemical composition parameters of the coating material by using polyolefin resin with specific molecular weight range (10,000-500,000) and polyolefin powder with controlled particle size (0.1-5mm). These parameter changes allow the material to achieve optimal flow characteristics at lower temperatures, reducing the cooling time while maintaining adequate viscosity for proper coating application
Solution Approach 2:
The invention uses a composite coating system consisting of multiple layers: adhesive layer (polymer concrete or epoxy-based), intermediate layer (polyolefin resin and polyolefin powder mixture), and outer layer (polyolefin). This composite structure allows each layer to perform its specific function, with the adhesive layer providing strong bonding, the intermediate layer providing insulation and mechanical protection, and the outer layer providing environmental resistance, thereby achieving rapid solidification without compromising protective properties
2Reliability
If thick insulating pipe coating is requested for deep water applications, then the insulation performance and hydrolysis resistance are improved, but the existing polypropylene injection system becomes incompatible due to extended cooling time requirements
Solution Approach 1:
The invention changes the physical parameters of the coating material by controlling the particle size of polyolefin powder (0.1-5mm) and molecular weight of polyolefin resin (10,000-500,000). These parameter changes enable faster heat transfer and solidification, allowing thick insulating coatings to be applied and solidified within the time constraints of offshore pipe laying operations, thereby maintaining compatibility with deep water applications
Solution Approach 2:
The invention applies preliminary heating to the pipe surface and coating materials before injection, and uses heated molds during the injection process. This preliminary action maintains the materials in a more fluid state longer, enabling thorough penetration and proper bonding even in thick sections, while the controlled cooling process afterward ensures rapid solidification that meets offshore installation time requirements
3Force
If powerful injection equipment and very solid mould construction are used to withstand high injection pressure, then the polypropylene can be injected, but the equipment complexity and cost increase
Solution Approach 1:
The invention changes the viscosity parameters of the coating material by selecting polyolefin resin with molecular weight of 10,000-500,000 and polyolefin powder with particle size of 0.1-5mm. These parameter changes ensure the material has adequate flow characteristics at processing temperatures, allowing injection at moderate pressures (5-20 MPa) that can be handled by standard injection equipment without requiring overly complex or heavily constructed systems
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 method enables rapid and effective coating of field joints with enhanced hydrolysis resistance and heat resistance, allowing for faster pipeline laying with improved insulation and mechanical properties, even at elevated temperatures, and reduces equipment complexity by using low viscosity formulations.
Implementation Method 1
injecting a field joint coating material based on a fast curable olefin liquid formulation... wherein the monomer is a norbornene-type cycloolefin monomer, and wherein the catalytic system is able to activate Ring Opening Metathesis Polymerisation of a norbornene-type cycloolefin
Implementation Method 2
applying a linear low-density polyethylene (LLDPE) resin having a maleic anhydride linear chain grafting or polypropylene resin having a maleic anhydride linear chain grafting
Implementation Method 3
applying an epoxy primer and maleic anhydride grafted polyethylene or polypropylene resins, and injecting a fast-curable olefin formulation... which allows for quick curing and chemical welding with the parent coating
Implementation Method 4
injecting a field joint coating material based on a fast curable olefin liquid formulation... wherein the monomer is a norbornene-type cycloolefin monomer... able to undergo polymerisation and optionally cross linking
Data Source
Figure 1~2
AI summary
The invention relates to a field joint coating material based on a fast curable olefin liquid formulation and a process of making a field joint wherein this coating material is used.