Comprehensive introduction of 3PE Coating anti-corrosion steel pipe

3PE, also called 3LPE, 3PE anti-corrosion steel pipe is a coating method for carbon steel pipe. 3PE anti-corrosion steel pipe refers to a steel pipe whose outer wall is protected by a three-layer polyethylene (3PE) anti-corrosion coating. 3PE anti-corrosion steel pipe parent materials include seamless steel pipes, spiral steel pipes and straight seam steel pipes. Whether it is welded steel pipes, stainless steel pipes, alloy steel pipes, nickel alloy pipes, CRA coated seamless steel pipes or lined pipes, 3PE can be applied to the pipes. The three-layer polyethylene (3PE) anti-corrosion coating has been widely used in the oil pipeline industry for its good corrosion resistance, water vapor permeability resistance and mechanical properties.

In addition to 2PE, 2PP and 3PP, 3PE coating is the most commonly used anti-corrosion method. The manufacturing processes of these coatings are similar, but the raw materials are different. The manufacturing process of this 3LPE is very simple. And it has good corrosion resistance and excellent anti-corrosion effect.

This cheap anti-corrosion process is widely accepted worldwide. 3PE can enhance the mechanical properties of the pipeline, high resistance, waterproof, wear-resistant, anti-aging, and protect the pipeline from heat loss, and the heat loss is only 1/4 of the pipeline.

3PE anti-corrosion layer structure

The 3PE anti-corrosion layer consists of three layers, each with a unique function, ensuring that the anti-corrosion layer provides lasting protection in various harsh environments.

1. Bottom layer: fusion-bonded epoxy (FBE, 60-80μm)

Main function: The bottom fusion-bonded epoxy is the key to the 3PE anti-corrosion layer. It can form a continuous coating and directly bond to the surface of the steel pipe. The fusion-bonded epoxy coating has excellent chemical corrosion resistance and anti-cathodic stripping properties, effectively preventing the intrusion of corrosive media. The adhesive of the bottom layer and the middle layer forms a strong bond through chemical reaction, thereby ensuring good adhesion of the anti-corrosion layer in high temperature environments.

2. Middle layer: Adhesive (170-250μm)

Main function: The middle layer is usually made of copolymer adhesive, the main component of which is polyolefin. The common middle layer adhesive is vinyl copolymer adhesive. Its polar part reacts with the epoxy group of the bottom fused epoxy to form hydrogen bonds or chemical bonds, ensuring good bonding between the bottom layer and the middle layer; and the affinity of the non-polar ethylene part with the surface polyethylene ensures the bonding performance between the middle layer and the surface layer.

3. Surface layer: extruded polyethylene (about 2mm)

Main function: The surface layer mainly provides mechanical protection and anti-corrosion. It can effectively resist physical damage and form a seal with the bottom and middle layers to prevent the intrusion of moisture and other corrosive media. The polyethylene of the surface layer has excellent chemical resistance and mechanical strength, and is an upgraded version of the traditional two-layer polyethylene anti-corrosion layer. .

In actual operation, the three materials are mixed into a whole, and after processing, they are firmly combined with the steel pipe to form an excellent anti-corrosion layer. Its processing methods are generally divided into two types: winding type and round die coating type.

Production line parameters:

(1) Steel pipe production range: 159mm-1600mm

(2) Processing capacity: ≤350㎡/h

(3) High-speed shot blasting, cleaning level: Sa2.5

(4) Raw materials used: steel sand, FBE powder, binder, polyethylene

(5) Microcomputer control automatically adjusts the coordination of various parts of the production line

(6) Product anti-corrosion life of 50 years

1. Excellent anti-corrosion performance: The 3PE anti-corrosion layer adopts a multi-layer structure, which effectively isolates the steel pipe from the external corrosive medium and prevents the corrosion of the steel pipe. Especially in humid, acidic, alkaline or salt spray environments, the 3PE anti-corrosion layer shows extremely excellent corrosion resistance.

2. Good resistance to mechanical damage: The extrusion process of the polyethylene surface layer makes it have a high impact resistance, which can effectively protect the steel pipe from external damage and is suitable for use during construction or transportation.

3. High temperature resistance: 3PE anti-corrosion layer can maintain good adhesion and stability at higher temperatures, adapt to various environmental conditions, and is especially suitable for pipelines under high temperature and harsh conditions.

4. Environmentally friendly: Since the 3PE anti-corrosion layer has strong UV resistance, it will not age or fall off even if exposed to the sun for a long time, maintaining the anti-corrosion effect.

3pe anti-corrosion spiral steel pipes are widely used in pipeline engineering fields such as petroleum, chemical, natural gas, thermal, sewage treatment, water sources, bridges, steel structures, and marine water piling, especially in the following scenarios:

Oil and gas pipelines: Since oil and gas pipelines often pass through harsh environments, 3PE anti-corrosion layer can effectively prevent corrosion and extend the service life of pipelines.

Chemical industry: Chemical pipelines are often exposed to corrosive environments, and 3PE anti-corrosion technology provides excellent anti-corrosion protection.

Urban water supply and heating system: 3PE anti-corrosion layer ensures the long-term stability and corrosion resistance of water supply and heating pipelines.