Automatic PLC Controlled 3LPE Coating Pipe Production Line for 30-50 Year Service Life in Harsh Environments

Product Overview

The 3-layer polyethylene (3LPE) anti-corrosion steel pipe production line is designed to apply a high-performance, multi-layer protective coating to steel pipes. By integrating advanced coating technology with premium materials, the system ensures long-term corrosion protection and durability for pipelines operating in harsh environments such as oil, gas, and water transportation.

Coating Structure

The production line applies a three-layer coating system, consisting of:

• Base Layer (FBE Epoxy Powder)
  Fusion Bonded Epoxy (FBE) is sprayed onto the steel pipe surface, forming a strong chemical bond and delivering excellent corrosion resistance.
• Middle Layer (Adhesive Layer)
  A copolymer adhesive layer ensures strong bonding between the epoxy base layer and the outer polyethylene layer.
• Outer Layer (HDPE Layer)
  High-Density Polyethylene (HDPE) is extruded as the outer layer, providing superior mechanical protection, low water absorption, and excellent environmental resistance.

This structure guarantees uniform coating, enhanced durability, and extended service life.

Key Advantages

• Excellent Sealing Performance
  Effectively prevents moisture ingress, reduces energy loss, and lowers operating costs.
• Outstanding Corrosion Resistance
  Provides long-term protection with a service life of 30–50 years.
• Superior Low-Temperature Performance
  Maintains strong adhesion and impact resistance in harsh, low-temperature environments.
• Optimized Material Combination
  Combines epoxy bonding strength, polyethylene impermeability, and adhesive flexibility for maximum reliability.
• Cost-Effective Solution
  High production efficiency with stable performance, compliant with international standards.

Technological Process

Pipe Loading → Screw Conveying → Shot Blasting → Induction Heating → FBE Coating → Adhesive & PE Extrusion → Cooling Spray → Pipe Conveying → End Grinding → Pipe Unloading

Main Equipment Configuration

A. Surface Treatment System

• Steel Pipe Conveyor (PLC controlled, adjustable speed/angle)
• Shot Blasting Machine
• Cyclone Dust Collector
• Cartridge Dust Collector
• Centrifugal Fan
• PLC Control System

B. Coating System

• Spiral Pipe Conveyor
• Induction Heating Machine
• Powder Spraying Device (80–800 μm thickness)
• Automatic Feeder & Dryer
• SJ-65/30 Extruder
• SJ-180/30 Extruder
• Adhesive & PE Die Heads (high-quality die steel)
• Adhesive/PE Coating Unit (silicone-coated pressure rollers)
• Environmental Ventilation System
• Cooling Spray System

C. Auxiliary Equipment

• Steel Pipe Platform

D. End Processing Equipment

• PE Beveling Machine
• Hydraulic Lifting & Turning Machine
• Hydraulic System

Applications

3LPE coated steel pipes are widely used in:

• Oil & Gas Transportation – long-distance pipelines
• Urban Gas Distribution Networks
• Water Supply Systems – municipal and industrial
• Chemical & Sewage Pipelines
• Other Fluid Transport Systems

Performance Benefits:

• High electrical insulation
• Waterproof and anti-corrosion
• Wear-resistant and anti-aging
• Enhanced mechanical strength

Company Profile

Qingdao Huashida Machinery Co., Ltd., established in 2003, is a leading manufacturer of plastic extrusion and pipe coating equipment. The company provides complete turnkey solutions, with over 70% of products exported to Europe, America, the Middle East, and Southeast Asia.