Plastic coating for pipelines and pipework

The plastic coating adheres tightly to the pipe surface, forming a robust protective barrier that effectively isolates the pipeline from external corrosive media, thereby significantly extending its service life. Whether underground or exposed to the atmosphere, plastic‑coated pipelines provide long‑term, reliable corrosion protection, reducing the risks of leaks and damage caused by corrosion and ensuring the safe operation of the piping system. In addition, coated pipes exhibit excellent wear resistance and impact resistance, enabling them to withstand a certain degree of mechanical damage while maintaining structural integrity and flow capacity. Moreover, the smooth surface of the coating features a low coefficient of friction, which helps reduce fluid resistance within the pipeline, enhances transport efficiency, and lowers energy consumption. From an environmental standpoint, plastic coatings are typically formulated with eco‑friendly, non‑toxic materials that do not contaminate the conveyed media, aligning with modern industrial demands for green and sustainable development. In summary, pipeline coating—owing to its outstanding corrosion resistance, wear and impact resistance, and environmental benefits—has found widespread application across sectors such as oil, chemical processing, natural gas, and water supply and drainage, serving as a critical means of ensuring the safe and efficient operation of piping systems.
Plastic-coated pipes use steel pipe as the base material, with a layer of plastic—such as epoxy resin—melt‑cured on the inner wall or both the inner and outer walls through processes like hot‑dip coating and electrostatic spraying. EP , polyethylene PE Steel–plastic composite pipes, formed through processes such as extrusion, combine the high strength of steel with the corrosion resistance and low hydraulic resistance of plastic. EP The coating is typically applied by electrostatic spraying, with a thickness of… 100 mu m-400 mu m ； PE The coating is typically applied using a hot-dip plasticizing process, with a thickness of 400 mu m — 1000 mu m Its greatest advantage is its excellent corrosion resistance; its smooth inner wall reduces friction, and it also provides electrical insulation to prevent leakage. Its design life can reach… 50 Year.

Core Features

-  Structural composition: The base pipe is made of carbon steel. / Seamless steel pipe, with epoxy resin as the primary coating material ( EP ), polyethylene ( PE ), polyvinyl chloride ( PVC ) and other organic polymers.

-  Performance advantages: corrosion resistance, anti-scaling, smooth inner wall with low flow resistance, high mechanical strength, and a design service life of up to 50  Year.

-  Thickness standard: EP Coating ≥ 100 mu m ， PE Coating ≥ 400 mu m (According to GB/T 28897-2021 ).

-  Caution: During installation, bending and welding are prohibited; cut edges must be repaired with a specialized non-toxic sealant to prevent corrosion.

Common Classification and Applications

1.  By coating location: internally coated pipe, externally and internally coated pipe.

2.  By material and application: EP Type (good temperature resistance, used for fire protection and hot water), PE Type (chemically resistant, used in the chemical industry and seawater), PVC Type (primarily used for drainage).

3.  Main applications: building fire sprinkler systems, domestic water supply and drainage, chemical‑resistant fluid conveyance, mining slurry transport, cable protection, and central air‑conditioning circulating systems.

Key Construction Points

-  Connection type: threaded ( DN15-DN100 ), groove ( DN65-DN400 ), flanges, or bimetallic welding.

-  Processing requirements: Cutting must be performed with a metal saw; after deburring, apply a curing adhesive. Direct arc‑welding cutting that damages the coating is strictly prohibited.

-  Implementation Standard: CJ/T 120-2016 “Plastic-Coated Steel Water Supply Pipes,” GB/T 28897-2021 Wait.