Custom Profiled Section Solution for Offshore LNG Project in Qatar
Project Overview
(From Left to Right: Hardtop XP, JotaPrime 510, HDG65um)
A flagship offshore liquefied natural gas (LNG) project in Qatar—operating in a highly corrosive marine environment—required specialized supporting components for cable tray systems to ensure long-term structural integrity and operational reliability. As a key supplier of custom infrastructure solutions, Shanghai Qiongkai Industrial Co., Ltd. was entrusted with delivering tailor-made profiled sections, designed to support critical cable management systems in this high-stakes energy project.
- Product Scope: Custom profiled sections (dimension: 50*50*23*23mm) for cable tray support
- Manufacturing Requirement: Non-standard profiled sections (special-shaped profiles) requiring precision CNC bending and laser cutting for punching
- Corrosion Protection System: Triple-layer coating with strict thickness and quality standards:
- Base layer: Hot-dip galvanization (HDG) with minimum zinc thickness of 65μm (compliant with GB/T 18226-2025)
- Intermediate layer: Jotun Jotaprime 510 heavy-duty anti-corrosion primer
- Top layer: Jotun Hardtop XP heavy-duty anti-corrosion topcoat
- Total coating thickness: 155-200μm (controlled within the specified range)
- Surface Quality Requirement: Zero zinc dross residue after hot-dip galvanization (critical for coating adhesion)
- Project Significance: Supporting critical cable systems in a high-corrosion offshore LNG environment
Core Challenges
The project presented unprecedented technical hurdles due to the combination of custom manufacturing and extreme corrosion protection requirements:
- Zinc Dross Removal Dilemma: Hot-dip galvanization of special-shaped profiles inherently generates zinc dross, but the client’s zero-dross requirement demanded a labor-intensive solution—without damaging the 65μm zinc layer.
- Uniform Coating on Special-Shaped Profiles: The non-standard 50*50*23*23mm profiled sections featured complex internal structures, making it extremely difficult to achieve uniform triple-layer coating.
- Precision Manufacturing of Custom Profiles: The absence of standard forming machine compatibility required CNC bending and laser cutting to achieve exact dimensions.
- Coating Compatibility: The triple-layer system (HDG + Jotun primer + Jotun topcoat) required strict process control to ensure adhesion between layers.
Innovative Solutions
Shanghai Qiongkai’s R&D and engineering teams developed a proprietary, precision-focused solution to address each challenge:
- Zinc Dross Removal Process: Implemented a custom manual grinding and polishing technique. This process utilized precision tools and controlled pressure to remove zinc dross residues—without reducing the zinc layer thickness below 65μm.
- Uniform Coating Technology: Optimized the coating application process for complex profiles, including custom fixture design for 360° coverage and adjusted spray parameters.
- Precision Custom Manufacturing: Deployed high-precision CNC bending machines (tolerance ±0.1mm) and fiber laser cutting equipment to produce the 50*50*23*23mm sections.
- Coating System Quality Control: Conducted interlayer adhesion tests (cross-cut method, GB/T 9286-1998) between hot-dip galvanization, primer, and topcoat.
Implementation
- Pre-Production Validation: Produced 5 prototype profiled sections to test precision and coating uniformity.
- Precision Manufacturing: Completed CNC bending and laser cutting with 100% dimensional inspection.
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Corrosion Protection Process:
- Hot-dip galvanization: Zinc layer thickness ≥65μm
- Zinc dross removal: Proprietary manual process
- Triple-layer coating: Jotun Jotaprime 510 and Jotun Hardtop XP
- Final Quality Inspection: Comprehensive testing for zinc layer thickness, total coating thickness, surface quality, and dimensional accuracy.
- Secure Delivery: Packaged in corrosion-resistant, shockproof materials for international shipping to Qatar.
Results & Value Delivered
- Technical Compliance: 100% pass rate in final inspection for dimensional precision and coating requirements.
- Extreme Corrosion Protection: Compliant with ISO 12944-5:2018 for C5-M marine category, with a projected service life of over 30 years.
- Structural Reliability: Stable support for the cable tray system, meeting offshore structural safety standards.
- Client Confidence: Demonstrated capability to deliver high-quality, custom solutions for extreme marine environments.
- Industry Benchmark: Set a precedent for custom profiled section manufacturing in high-corrosion offshore applications.
Key Takeaways
This case study highlights Shanghai Qiongkai Industrial Co., Ltd.’s expertise in addressing the most demanding requirements of offshore energy projects. By combining precision custom manufacturing with innovative corrosion protection solutions, we overcame core technical bottlenecks while adhering to strict quality requirements. The success underscores our commitment to technical innovation and quality excellence—critical capabilities for the global offshore LNG and marine infrastructure sectors.