MAKSPC

Three-layer polyethylene (3LPE) coating is a widely used anti-corrosion protective system applied to steel pipes, typically for use in buried or submerged pipelines, such as those for gas, oil, and water transportation. This type of coating provides excellent corrosion protection and high mechanical strength, ensuring that pipes withstand harsh environmental conditions.

Structure of 3LPE Coating

The three layers in the 3LPE coating system are:

1. Epoxy Primer Layer (First Layer):

• Material: Fusion-bonded epoxy (FBE).
• Purpose: Provides corrosion resistance and excellent bonding to the steel pipe surface.
• Application: Applied directly to the pipe after surface cleaning (typically through sandblasting or shot blasting).
• Benefits: This layer protects the pipe against corrosion and enhances adhesion with the polyethylene outer layers.

2. Adhesive Layer (Second Layer):

• Material: Copolymer adhesive (usually a co-extruded adhesive or grafted copolymer).
• Purpose: Bonds the epoxy layer to the polyethylene outer layer.
• Application: Melted and applied over the epoxy primer.
• Benefits: Ensures strong adhesion between the epoxy and the outer polyethylene layer, providing a uniform and durable coating.

3. Polyethylene Layer (Third Layer):

• Material: High-density polyethylene (HDPE).
• Purpose: Provides mechanical protection against impact, abrasion, and soil stress.
• Application: Extruded as the outermost layer, covering the adhesive layer.
• Benefits: This layer offers excellent impact resistance, protecting the pipe during handling, installation, and operation.

Advantages of 3LPE Coating

• Enhanced Corrosion Resistance: Protects steel from moisture and contaminants.
• High Impact and Abrasion Resistance: Reduces the risk of damage during transportation and installation.
• Good Thermal Resistance: Performs well at varying temperatures.
• Long-Term Performance: Provides a lifespan of several decades under proper conditions.
• Environmental Stress Resistance: Can endure mechanical stresses from the surrounding environment.