Plastic-coated spiral steel pipe is a composite pipe with plastic material coated on the inner and outer surfaces of spiral steel pipe through a special process. Spiral steel pipe is made of strip steel coil as raw material, formed and welded, and is widely used in petrochemical, municipal water supply, and drainage and other fields; polyethylene (PE) and epoxy resin (EP) are commonly used for plastic coating. The former is corrosion-resistant and waterproof, affordable, and suitable for underground pipelines; the latter is chemically stable and has high strength, and is suitable for special fields such as the chemical industry, oil, and gas.
It combines the characteristics of steel pipe and plastic, and has the advantages of high strength, impact resistance, pressure bearing capacity, corrosion resistance, chemical resistance, and low friction resistance. It can work stably for a long time in corrosive medium transportation scenarios, reducing replacement and maintenance costs.
First, the unique advantages of plastic-coated spiral steel pipe
1. Excellent corrosion resistance: The plastic coating can resist erosion by acids, alkalis, salts, etc., and can operate stably for 30-50 years in complex environments such as municipal sewage pipes, greatly extending life and reducing costs.
2. Excellent wear resistance: The coating has high hardness and good wear resistance, and can withstand the impact and friction of solid particles. In scenarios such as mines and power plants, the wear rate is much lower than that of ordinary steel pipes, ensuring continuous production.
3. Good pressure resistance: Inheriting the high strength of steel pipes, it can withstand internal high pressure and external pressure, suitable for long-distance transportation of oil and natural gas, and reliable operation under high pressure, deep burial, and other working conditions.
4. Environmental protection and energy saving: Environmentally friendly materials are used, and production and use are pollution-free; good thermal insulation and smooth inner walls can reduce transportation energy consumption, and the materials can be recycled after scrapping, which is in line with the concept of sustainability.
Second, the production process of plastic-coated spiral steel pipes
1. Steel pipe pretreatment: Remove surface oxide scale, oil stains, and other impurities through sandblasting and shot blasting, increase roughness, and lay the foundation for coating adhesion. This link accounts for about 70% of the impact on quality.
2. Primer spraying: Use epoxy or polyurethane primers. The former is anti-corrosion and rust-proof, with strong adhesion, and the latter is friction-resistant and flexible. It needs to be sprayed evenly to ensure moderate thickness.
3. Powder coating spraying: the core link, using electrostatic adsorption to make the powder particles adhere to the surface of the steel pipe to form a uniform coating. There are various types of coatings, each with its own applicable scenarios.
4. Curing, baking, and quality inspection: After spraying, high-temperature baking is used to solidify the coating, and the temperature and time must be strictly controlled; after cooling, quality inspection, including appearance, thickness, adhesion, etc., can be shipped only after passing the inspection.
Third, the application field of plastic-coated spiral steel pipe
1. Municipal water supply and drainage engineering: used for tap water pipe network to ensure water quality safety and extend the life of the pipe network; corrosion-resistant and wear-resistant in sewage system to reduce leakage and blockage; ensure stable water supply in fire protection system.
2. Petrochemical industry: resist corrosive components in oil and gas, ensure safe transportation, undertake the transportation tasks of crude oil, chemical raw materials, etc., and ensure continuous production.
Power industry: protect cables from damage and extend their life; serve as support or transportation pipelines in traffic bridges, airports, industrial parks, etc. to meet various needs.
Fourth, the market status and future trends of plastic-coated spiral steel pipes
1. Market competition pattern: There are many manufacturers, and large enterprises dominate the market with their advantages in technology, equipment, and capital. Small enterprises are limited by conditions and have unstable quality. They rely on low prices to compete and disrupt the market order.
2. Future development trends: With the continuous growth of demand, the advancement of industrialization and urbanization, and the “Belt and Road” initiative, there is a broad space for application in infrastructure and other fields at home and abroad.
Fifth, selection, installation, and maintenance of plastic-coated spiral steel pipes
1. Selection points: Check the manufacturer’s qualifications and test reports, check the appearance quality, judge the performance through physical tests or professional tests, and ensure that the use requirements are met.
2. Installation and maintenance: Select flanges, grooves, welding, and other connection methods according to the working conditions, and install them strictly according to the specifications; conduct regular daily inspections, clean the interior, strengthen protection in harsh environments, and avoid external damage.
In summary, plastic-coated spiral steel pipes have excellent performance, wide application, and broad prospects. Mastering the correct selection and use methods can give full play to their advantages and help infrastructure and industrial development.
Post time: Jul-02-2025