In 2015, we processed and constructed the entire offshore oil pipeline gallery at Pengerang, Malaysia, utilizing steel structure modules for assembly and offshore installation. For marine corrosion protection, we strictly adhered to standard requirements throughout fabrication, transportation, assembly, and offshore deployment, ensuring thorough paint application to guarantee the gallery’s normal operation for 15 years at the terminal.
Steel structures located in coastal or offshore environments face extreme corrosion challenges due to high salt exposure, humidity, UV radiation, and harsh marine climates. Ensuring high-quality corrosion protection is essential to structural safety, service life, and long-term maintenance cost control.
Below is a professional, client-oriented explanation of how corrosion protection quality is ensured for marine and coastal steel structures.
1. Corrosion Protection Design Based on Environmental Classification
Coastal and offshore steel structures are typically classified as severe or extreme corrosion environments, such as:
- Coastal areas: C4 / C5-M
- Offshore structures: C5-M / CX
(According to ISO 12944, AISC, and ASTM standards)
Design drawings and specifications should clearly define:
- Design service life
- Protection system
- Total dry film thickness (DFT)
- Inspection and maintenance requirements
2. High-Performance Corrosion Protection Systems
1) Hot-Dip Galvanizing + Heavy-Duty Coating System
One of the most proven solutions for marine environments:
- Inner layer: Hot-dip galvanizing (ASTM A123 / ISO 1461)
- Outer layers: Zinc-rich epoxy primer, epoxy intermediate coat, polyurethane or fluorocarbon topcoat
This system can achieve a service life of 25–40 years in marine conditions.
2) Thermal Metal Spraying (Zn / Al / Zn-Al)
Widely used for:
- Offshore platforms
- Marine bridges
- Port and jetty structures
Advantages:
- Excellent salt spray resistance
- Easy local repair
- Compliant with ASTM A780 and ISO 2063
3) Marine-Grade Coating Systems
For projects with higher durability or aesthetic requirements:
- Epoxy glass flake coatings
- High-solids epoxy systems
- Marine-grade polyurethane or fluoropolymer coatings
3. Surface Preparation: The Key to Long-Term Performance
Most corrosion failures result from insufficient surface preparation rather than coating quality.
Typical requirements include:
- Blast cleaning to Sa2.5 / SSPC-SP10
- Controlled surface roughness per coating TDS
- Grinding and rounding of welds, edges, and corners
All requirements must be specified in design drawings and method statements.
4. Full Quality Control and Inspection
To ensure long-term protection, a complete inspection regime is essential:
- Environmental monitoring (temperature, humidity, dew point)
- Dry film thickness (DFT) measurement
- Adhesion testing
- Holiday detection
- Galvanizing thickness and zinc content testing
Third-party inspection is strongly recommended to ensure compliance with ASTM, SSPC, and ISO standards.
5. Customer Value: Lower Lifecycle Cost
A high-quality marine corrosion protection system delivers:
- 2–3 times longer service life
- Reduced maintenance and downtime
- Improved structural safety
- Compliance with international and government project requirements
Corrosion protection for coastal and offshore steel structures is a comprehensive engineering process—not a single coating step.
With proven marine corrosion expertise and strict adherence to international standards, we provide reliable, long-life corrosion protection solutions tailored to demanding environments.
In recent years, we have completed projects such as the Fuqing Nuclear Power Plant, the Japan BV Substation, and the Indonesia Concentrate Storage Facility. As these projects are all located near the coast, they demand exceptionally high corrosion protection standards. Most employ a dual-protection approach combining hot-dip galvanizing with paint coating.
We hope to provide you with more specialized guidance on steel structure corrosion protection!