Hello Pipe Enthusiasts!
Welcome back to #SEAPIPipeInsights, previously we discussed "Safety and Durability of Steel Pipes: Preventing Corrosion and Damage”. This time we will cover the most common external protective coatings for steel pipes: Fusion Bonded Epoxy (FBE), Three-Layer Polyethylene (3LPE), and Three-Layer Polypropylene (3LPP). Understanding the differences among these coatings is important for those working in oil & gas, infrastructure, and water utility industries.
What Is External Coating on Steel Pipes?
External coating is a protective layer applied to the outside surface of steel pipes to prevent corrosion, mechanical damage, and environmental degradation. Without this protection, pipes are exposed to moisture, chemicals, and abrasion that shorten their service life.
1. Fusion Bonded Epoxy (FBE)
Fusion Bonded Epoxy (FBE) is a thermofused epoxy layer applied electrostatically to a heated pipe. After heating, the epoxy layer melts and adheres strongly to the steel.
- Application: Water pipes, water injection, and light oil
- Standard thickness: 125 - 400 μm
- Advantages: High adhesion, chemical resistance, smooth surface
2. Three-Layer Polyethylene (3LPE)
Three-Layer Polyethylene (3LPE) combines an adhesive layer, a middle polyethylene layer, and an epoxy corrosion barrier layer.
- Application: Oil & gas pipelines, underground lines
- Standard thickness: 500 - 3800 μm
- Advantages: Excellent corrosion resistance, high flexibility, damping resistance
3. Three-Layer Polypropylene (3LPP)
Three-Layer Polypropylene (3LPP) is similar to 3LPE but uses polypropylene as the middle layer.
- Application: Oil & gas, marine and tundra environments
- Standard thickness: 600 - 3800 μm
- Advantages: Higher thermal stability, excellent UV and abrasion resistance
Comparison of FBE, 3LPE, and 3LPP
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Criteria
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FBE
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3LPE
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3LPP
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Standard Coating Thickness
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125–400 μm
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500 μm / 0.5 mm – 3800 μm / 3.8 mm
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600 – 3800 μm / 3.8 mm
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Standard Corrosion Resistance
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Good at ≤ 150 °C
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Excellent at ≤ 80 °C
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Good up to 110 °C
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Flexibility
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Moderate, prone to cracking
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High, resistant to moderate bending
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Highest, resistant to degradation
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Mechanical Properties
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Hard & brittle
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Balanced hardness & elasticity
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Combination of hardness & high flexibility
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Common Applications
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Water, light oil & gas
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Oil & gas, underground
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Oil & gas, marine, extreme tundra
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Choosing the Right Coating
- For industrial water or Non Oil & Gas applications: consider FBE or galvanizing if budget is limited.
- For onshore oil & gas pipelines: 3LPE offers a balance of corrosion protection and flexibility.
- For marine or extreme temperature environments: 3LPP excels in thermal stability and UV resistance.
Also consider overall cost factors, availability of application equipment, and applicable inspection protocols.
By understanding the characteristics of FBE, 3LPE, and 3LPP, you can choose the most appropriate solution for your project requirements. We hope this article helps Pipe Friends in designing and operating piping systems that are durable, safe, and efficient.
Don’t forget to share your insights in the comments, and keep following updates on pipe technology exclusively at #SEAPIPipeInsights!. If you need high-quality steel pipe coating solutions that meet national and international standards, please contact our Marketing & Sales team. PT Southeast Asia Pipe Industries is ready to support your project.
