First, the principle of anti-corrosion steel pipes
Coating anti-corrosion is an evenly dense coating formed on the surface of the rust-free metal pipe, and the coating can isolate it from various corrosive media. Steel pipe anti-corrosion coatings are increasingly using composite materials or composite structures.
Exterior wall anti-corrosion coatings: Types and application conditions of coatings on the outer wall of steel pipelines. Inner wall anti-corrosion coatings This film is applied to the inner wall of the pipeline to prevent pipeline corrosion, reduce friction resistance, and increase dosage. Commonly used coatings are amine-cured epoxy resins and polyamide epoxy resins, with a coating thickness of 0.038 to 0.2 mm. To ensure that the coating is firmly bonded to the steel pipe wall.

The inner wall of the steel pipe must be treated on the surface. Since the 1970s, the same material has been used to coat the inner and outer walls of steel pipelines, so that the inner and outer walls of steel pipelines can be coated at the same time. Anti-corrosion and thermal insulation coatings are used on small and medium-caliber heat transfer crude oil or fuel oil pipelines to reduce the heat dissipation of steel pipelines to the soil.

A composite layer of heat preservation and corrosion resistance is added to the outside of the steel pipe. The commonly used insulation material is rigid polyurethane foam, which is suitable for temperatures of. This material is soft. To increase its strength, a high-density polyethylene layer is applied to the outside of the insulation layer to form a composite material structure to prevent open water from penetrating the insulation layer.

Second, what is a 3PE anti-corrosion steel pipe?
As a terminal technology product of the steel pipe industry chain, anti-corrosion steel pipe has always occupied a very important position in the industry. In recent years, with the development and application of new steel pipe anti-corrosion technologies, anti-corrosion steel pipes have been used more and more widely in engineering, and many factories specializing in anti-corrosion steel pipe processing have sprung up like mushrooms after rain. 3PE anti-corrosion steel pipe is an important variety of anti-corrosion steel pipe. 3PE anti-corrosion steel pipe is a three-layer polyolefin coating (MAPEC) anti-corrosion steel pipe commonly used in my country. The base material of the steel pipe mainly includes seamless steel pipe, spiral structure steel pipe, straight seam welded pipe, etc.

The first layer of epoxy powder (FBE ＞ 100 μm)
The second layer uses adhesive (AD) 170 ~ 250 um
The third layer of polyethylene is 2.5 ~ 3.7mm

In practice, these three materials are mixed, processed, and firmly mixed with the steel pipe to form an excellent anti-corrosion coating. The processing technology methods can generally be divided into two types: winding type and round die coating type. The bottom layer of 3PE anti-corrosion steel pipe coating is in contact with the surface of the steel pipe coated with epoxy powder anti-corrosion coating. The middle layer is a copolymer adhesive with a branched structure-function, and the surface layer is a high-density polyethylene anti-corrosion coating. 3PE anti-corrosion steel pipe coating (three-layer polyethylene anti-corrosion coating) is a new type of anti-corrosion steel pipe coating that combines European 2PE anti-corrosion coating and epoxy powder anti-corrosion pipe coating (FBE). It has been widely used in North America in the early days, and now it has been used for decades.

3PE anti-corrosion technology and coatings can combine the high impermeability and high mechanical system performance of epoxy resin and polyethylene. So far, it has been widely used in many projects.

As for the use of 3PE anti-corrosion steel pipes, it covers a wide range. It is suitable for underground water supply and drainage, underground spraying, positive and negative pressure ventilation, gas discharge, fire spraying, and other pipe networks; thermal power plant waste slag and process water return water for transportation system pipelines; it also has good applicability to the water supply pipeline of the automatic sprinkler fire extinguishing system; it can also be used for power supply, communication, road, and other cable protection working casings.

The long-term use of 3PE anti-corrosion and thermal insulation steel pipes can reduce production costs and have relatively strong waterproof and anti-corrosion capabilities. It can be directly buried underground or in water without the need for attached pipe trenches. The construction is simple and fast, and the comprehensive management cost control is relatively low.