3PE anti-corrosion pipe manufacturing process

The 3PE (Three-layer Polyethylene) anti-corrosion pipeline is widely used for its excellent corrosion resistance and mechanical properties. The 3PE coating process involves applying three distinct layers onto the pipe surface, ensuring long-term protection against corrosion, especially in harsh environments such as underground and underwater.

3PE Coating Layers:

- First Layer - Fusion Bonded Epoxy (FBE):

This layer is applied directly onto the cleaned pipe surface to provide strong adhesion to the metal and serve as a corrosion barrier.

- Second Layer - Adhesive:

This layer bonds the epoxy layer to the polyethylene layer, enhancing the overall adhesion and preventing delamination.

- Third Layer - Polyethylene (PE):

The outermost layer provides mechanical protection and enhances the corrosion resistance of the pipeline.

Manufacturing Process:

- Surface Preparation:

Cleaning: The pipe surface is cleaned using abrasive blasting to remove rust, mill scale, and other contaminants. This ensures proper adhesion of the coating.

Pre-heating: The pipe is pre-heated to a temperature of about 200-250°C to ensure that the subsequent layers bond effectively.

- Application of Fusion Bonded Epoxy (FBE):

Epoxy Powder Coating: The FBE powder is sprayed onto the pre-heated pipe surface. The heat causes the epoxy to melt and form a continuous, adherent film over the pipe surface.

- Application of Adhesive Layer:

Adhesive Application: A layer of adhesive is applied over the FBE coating. This adhesive is usually a copolymer adhesive that ensures a strong bond between the epoxy and polyethylene layers.

- Application of Polyethylene Layer:

Extrusion Coating: The polyethylene layer is extruded and applied over the adhesive layer. The hot polyethylene layer fuses with the adhesive, forming a continuous, protective outer layer.

Cooling and Inspection:

Cooling: The coated pipe is cooled using air or water spray to solidify the layers and ensure a durable coating.

Inspection: The coated pipes undergo thorough inspection and testing to ensure the coating's integrity and adhesion. This may include visual inspection, thickness measurement, holiday detection, and peel tests.

Key Benefits of 3PE Coating:

Excellent Corrosion Resistance: The multi-layer structure provides superior protection against chemical and moisture-induced corrosion.

Enhanced Mechanical Protection: The polyethylene outer layer provides strong resistance to mechanical damage during handling, transportation, and installation.

Long-term Durability: The 3PE coating ensures a long service life for pipelines, reducing maintenance costs and downtime.

Versatility: Suitable for use in a variety of environments, including underground and underwater applications.

Applications:

Oil and Gas Pipelines: Used for transporting oil, gas, and other petroleum products in corrosive environments.

Water Supply Pipelines: Ideal for drinking water and sewage pipelines, providing reliable protection against corrosion and contaminants.

Industrial Pipelines: Used in various industrial applications where pipes are exposed to aggressive chemicals and environmental conditions.