Plastic-coated Steel Pipes

Plastic-coated steel pipes (also known as plastic-lined/coated steel pipes) are composite pipeline products that combine the mechanical strength of steel pipes with the corrosion resistance, hygiene, and smoothness of plastic materials. The plastic coating (or lining) is applied to the inner and/or outer surfaces of carbon steel or stainless steel pipes via processes like extrusion, fusion bonding, or electrostatic spraying. This design addresses the limitations of single-material pipes (e.g., steel’s poor corrosion resistance, plastic’s low pressure-bearing capacity), making them widely used in municipal water supply, chemical engineering, food processing, and oil/gas industries. Below are their core product features:

1. Superior Corrosion Resistance (Core Advantage)

• Multi-Material Coating Options for Diverse Environments:

• Polyethylene (PE): Cost-effective, resistant to water, salts, and mild acids/alkalis—ideal for municipal water supply, drainage, and outdoor buried pipelines.

• Polypropylene (PP): High-temperature resistant (up to 100°C) and chemical-stable, suitable for industrial fluid transmission (e.g., dilute acids, alkalis, and organic solvents).

• Polyvinyl Chloride (PVC): Rigid, wear-resistant, and low-cost, used in low-pressure scenarios like agricultural irrigation or indoor plumbing.

• Fusion-Bonded Epoxy (FBE): Heat-cured, high-adhesion coating for high-pressure oil/gas pipelines, resisting H₂S and saltwater corrosion.

• Dual-Side Protection (Inner + Outer Coating):
  Outer plastic coating prevents corrosion from soil, groundwater, or atmospheric exposure (e.g., UV rays, rain); inner coating avoids internal corrosion from transported media (e.g., acidic water, chemicals) and prevents steel ions from leaching into fluids (critical for drinking water or food-grade applications).

2. High Mechanical Strength & Pressure-Bearing Capacity

• Load-Bearing & Pressure Resistance:
  The steel core provides high tensile strength (≥345MPa for Q235 carbon steel) and yield strength (≥235MPa), enabling the pipe to withstand working pressures of 1.0–6.4MPa (depending on steel grade and wall thickness). This makes it suitable for high-pressure scenarios like industrial process pipelines or fire sprinkler systems—unlike pure plastic pipes, which deform under high pressure.

• Impact & Wear Resistance:
  The steel base resists external impact (e.g., construction machinery collisions, soil extrusion during burial), while the plastic coating (especially PE/PP) reduces internal wear from fluid turbulence or solid particles (e.g., sewage with sediments). This extends service life in harsh installation or operation environments.

Main application fields

Water supply and drainage pipes

Fire sprinkler system Natural gas, gas, oil pipeline Chemical, pharmaceutical, food pipeline Slurry, powder, sand and gravel pipeline Cable protection conduit