Specification details of galvanized plastic-coated steel pipe

First, an introduction to galvanized plastic-coated steel pipe

Galvanized plastic-coated steel pipe is a composite pipe that combines galvanizing and plastic-coating processes. It uses a steel pipe as the base and forms a galvanized layer and a plastic-coated layer on the inner and outer surfaces after processing.

The two protective layers have their own functions: the galvanized layer resists corrosion from the atmosphere, water quality, soil, etc., and the plastic-coated layer enhances chemical corrosion resistance and wear resistance. The double protection makes its performance outstanding.

It is widely used in construction, municipal administration, industry, and other fields. In humid underground environments, it can operate stably, greatly extend its service life, and reduce maintenance costs compared to ordinary steel pipes that are prone to rust.

Second, the manufacturing process of galvanized plastic-coated steel pipe

The manufacturing process of galvanized plastic-coated steel pipe is complex and delicate, and each link has a significant impact on product performance.

Galvanizing adopts the hot-dip galvanizing method: first pre-treat the steel pipe, remove surface rust, scale, and other impurities through pickling to expose the pure metal matrix. For example, some companies will strictly control the acid concentration and pickling time to ensure cleanliness; after pickling, wash with ammonium chloride or zinc chloride aqueous solution to neutralize the residual acid; then immerse the steel pipe in 450℃-480℃ molten zinc liquid, and form a tight and uniform zinc-iron alloy layer and pure zinc layer through physical and chemical reactions, which improves corrosion resistance and firmly combines with the matrix, and can extend the corrosion resistance life of the steel pipe in the atmospheric environment.

The plastic coating process is carried out after galvanizing: first, sandblasting is performed, and quartz sand and other spray materials are sprayed on the steel pipe surface at high speed with compressed air to increase the roughness to enhance the adhesion of the plastic coating layer; then the steel pipe is preheated to 100℃-300℃ (adjusted according to the coating material and specifications); then electrostatic spraying is performed to make epoxy resin, polyethylene and other powder coatings adsorbed on the surface under the action of high-voltage static electricity; finally, it is sent to the curing furnace, and the coating solvent is evaporated and the coating cross-linked by heating to form a hard and wear-resistant coating. The temperature and time must be strictly controlled during curing to ensure quality.

Third, the performance of galvanized plastic-coated steel pipes is revealed.

Galvanized plastic-coated steel pipes have excellent performance and significant advantages.

- Extremely strong corrosion resistance: The galvanized layer reacts with oxygen to form a dense zinc oxide protective film, like a solid armor to block oxygen and moisture, and it is not easy to rust in a humid environment; the plastic coating layer (such as epoxy resin, polyethylene) is resistant to chemical substances such as acids, alkalis and salts. The double protection allows it to operate stably for a long time in harsh environments such as chemical workshops, reducing the frequency of replacement and corporate costs.

- Excellent mechanical strength: Inheriting the high-strength characteristics of steel pipes, it is resistant to pressure and external impact, and is not easy to deform and damage. It can stably support the system during construction and cope with complex conditions; in earthquake-prone areas, it can withstand vibration displacement with strength and flexibility, reduce the risk of rupture and leakage, and ensure the safety of water supply and gas supply systems.

- Excellent hygienic performance: It adopts modified food-grade epoxy or polyethylene coating, which is non-toxic and odorless and does not pollute the conveying medium. When used for domestic drinking water transportation, it meets the hygienic standards to ensure the purity and safety of water quality. It is widely used in areas with high hygienic requirements such as building water supply and drainage, food and beverage transportation, and protects health.

- Low fluid resistance: The inner wall is smooth. Compared with ordinary steel pipes, the resistance is reduced by about 30% under the same conditions, and a larger flow rate can be transmitted. In urban water supply systems, it can reduce water pump energy consumption, reduce costs, and improve water supply efficiency, ensuring that residents have stable and sufficient water.

Fourth, the application field of galvanized plastic-coated steel pipes

- Construction industry: Galvanized plastic-coated steel pipes are widely used in the construction field. In indoor water supply and drainage systems, its excellent hygienic performance and corrosion resistance ensure the safe transportation of domestic water, avoid water pollution, and improve living quality. In building fire protection systems, it can withstand the high-pressure impact of fire water with its high strength and corrosion resistance, providing protection for firefighting, such as the connection of fire equipment in large commercial complexes. In addition, in building ventilation systems, due to its smooth inner wall and good corrosion resistance, it can reduce air resistance and ensure the efficient operation of the system.

- Municipal engineering: It plays a key role in municipal engineering. The urban water supply network uses it. With its corrosion resistance and long life, it can operate stably in complex underground environments for a long time. After a city's water supply transformation replaced the old steel pipe with it, the water leakage rate was reduced and the water supply stability was improved. In urban drainage systems, it can resist corrosive substances in sewage and prevent perforation. Coastal cities use it as drainage steel pipes to extend life and reduce maintenance costs.

- Chemical industry: Because it can resist the erosion of a variety of chemical substances, it meets the industry's high requirements for the transportation of highly corrosive media. It is commonly used for the transportation of media such as acids, alkalis, and salts. For example, sulfuric acid production companies use it to transport concentrated sulfuric acid, and the petrochemical industry uses it to transport crude oil and natural gas. It relies on sealing and corrosion resistance to prevent leakage and reduce safety risks.

- Other fields: In agricultural irrigation, it can withstand water pressure, resist soil corrosion, ensure the stable operation of the irrigation system, improve the utilization rate of water resources, and large farms use it to reduce maintenance costs and improve irrigation uniformity. In the power industry, it can be used as a cable protection tube to protect the cable from damage such as ultraviolet rays and rain, ensure safe and reliable power transmission, and extend the life of the cable.

Fifth, the comparative advantages of galvanized plastic-coated steel pipes and other pipes

- Compared with ordinary steel pipes: ordinary steel pipes have poor corrosion resistance, are easy to rust, require frequent maintenance, and have high costs; galvanized plastic-coated steel pipes are double-protected, and the corrosion resistance is greatly improved, the life is extended several times to dozens of times, and the maintenance cost is low. And its plastic coating can provide buffer protection, and has better impact resistance and deformation resistance.

- Compared with plastic pipes: plastic pipes are light and low-priced, but have low strength, are not resistant to high temperatures, and have a narrow range of applications; galvanized plastic-coated steel pipes combine the advantages of steel and plastic, have high strength, are resistant to high temperatures, and are suitable for complex working conditions. Food-grade coatings guarantee hygiene and safety more guaranteed, and are more suitable for food and beverage transportation and other fields.

- Compared with ductile iron pipes: Ductile iron pipes are heavy, with high transportation and installation costs and difficulties, poor corrosion resistance, and rough inner wall resulting in large fluid resistance; galvanized plastic-coated steel pipes are light, with high construction efficiency, better corrosion resistance, smooth inner wall resulting in low fluid resistance, low energy consumption, and high transportation efficiency.

Sixth, market prospects

Looking to the future, the market prospects of galvanized plastic-coated steel pipes are bright. With the continuous advancement of the global industrialization process and the continuous acceleration of urbanization construction, the demand for various high-performance steel pipe materials is growing. Galvanized plastic-coated steel pipes stand out among many steel pipe materials with their excellent performance advantages, and will usher in a broader development space.