TPEP anti-corrosion steel pipe

TPEP anti-corrosion steel pipe, also known as outer wrapped polyethylene and inner fusion bonded epoxy anti-corrosion pipeline, is an upgraded product based on the outer single-layer polyethylene and inner epoxy composite steel pipe. It is currently an excellent form of steel pipe anti-corrosion for buried long-distance pipelines.

Basic information

Name meaning

In TPEP, "T" is the first letter of "Two" and "Three", indicating two or three layers; PE "refers to polyethylene; EP "refers to hot-melt bonded epoxy resin powder.

Performance characteristics

Corrosion Resistance

The use of anti-corrosion coatings to shield the inner and outer wall surfaces is a commonly used protective measure. The outer wall is coated with a three-layer structure of polyethylene heavy-duty anti-corrosion coating, with a thickness of ≥ 2.5mm, in accordance with the standard "GB/T Polyethylene Anti corrosion Coating for Buried Steel Pipelines"; The inner wall is coated with hot-melt epoxy resin powder, with a thickness of ≥ 350 μ m, in accordance with the standard "CJ/T Water Supply Coating Plastic Composite Steel Pipe". The anti-corrosion of the pipe fittings is the same as that of the steel pipe body. This combination of three-layer polyethylene coating and fusion bonded epoxy powder coating technology provides a good solution for corrosion protection of buried steel pipes, greatly improving coating adhesion and thickness, enhancing resistance to bumps and corrosion, and having strong anti-corrosion performance, generally up to 50 years of use.

hydraulic performance

The inner wall of the pipeline is smooth with a roughness of 0.0081-0.0091 (tested by the Testing Center of the Water Resources Research Institute), and the head loss is small. When conveying media of the same flow rate, the diameter of the pipeline can be reduced by one level. Compared with pipes of the same diameter, pipelines with inner wall fusion bonded epoxy coating can reduce losses by more than 30%. At the same time, the inner wall meets the national hygiene standards, is smooth and not easy to scale, has self-cleaning function, and can effectively prevent secondary pollution of water quality, which has a significant effect on improving water quality.

Mechanical properties

Combining the mechanical strength of steel pipes and the corrosion resistance of plastics, it has superior ductility and integrity. It has stronger resistance to water hammer than ductile iron pipes, stronger adaptability to terrain, and good flexibility of steel pipes.

Production process

External wall anti-corrosion process

Adopting hot melt bonding and wrapping technology, the bottom layer is made of epoxy resin, the middle layer is adhesive, and the outer layer is made of polyethylene, forming a three-layer anti-corrosion layer structure.

Inner wall anti-corrosion process

Using thermal spray epoxy powder anti-corrosion method, the powder is uniformly coated on the surface of the pipe body after high-temperature heating and fusion, forming a steel plastic alloy layer.

Composite technology of base pipe and coating

Preheat the base pipe first to ensure that the surface temperature meets the temperature requirements of the plastic powder, and control it at a higher temperature before applying the plastic powder. The powder coating method can be divided into spraying (spraying plastic powder through a nozzle with compressed air), suction coating (creating negative pressure inside the tube with a vacuum pump to suck the plastic powder in), impregnation (storing the plastic powder in a container and immersing the preheated base tube in the powder), and rolling molding (storing the plastic powder on the wall of the base tube and rotating and rolling the base tube to evenly distribute the powder). As the surface of the base pipe reaches the rated temperature, the plastic powder melts and coats the pipe wall, forming a coating or anti-corrosion layer.

Connection method

Welding is used, and the inner wall is repaired with two-component liquid epoxy repair agent, while the outer wall is repaired with heat shrink tape or heat shrink sleeve.

application area 

Suitable for various fields such as marine facilities, petrochemicals, construction industry, and other industrial and mining enterprises, the anti-corrosion of steel structure equipment, various storage tanks, transportation pipelines, and other steel materials. It mainly undertakes the transportation of sewage generated in human life processes and is also an ideal choice for water supply pipelines such as water plants.