9 Principles And Structures Of 3lpe Coated Steel Pipes

Introduction

3lpe coated steel pipe literally means a PE steel pipe with three layers of anti-corrosion. 3lpe anti-corrosion steel pipe is widely used today and is a steel pipe with relatively good anti-corrosion properties. 3lpe coated steel pipes comply with DIN 30670 standards. 3lpe anti-corrosion steel pipes are mainly composed of two parts, one is the anti-corrosion layer and the other is the steel pipe. The main steel pipes include spiral steel pipes, straight seam steel pipes and seamless steel pipes.

The 3PE anti-corrosion layer implements the ISO 21809-1 standard. ISO 21809-1 greatly improves the peel strength and impact resistance indicators of the 3PE anti-corrosion layer, and clearly stipulates that the mechanical strength and impact resistance of the 3PE anti-corrosion layer will be enhanced according to the carbon black content of some special materials. Weather resistance performance, and increased the frequency of spot testing of patching peel strength (i.e., the peel strength of heat shrink sleeves and heat shrink tapes against primer steel).

The thickness of the outer anti-corrosion layer is determined according to the German standard DIN30670-1991, which is mainly low and medium density polyethylene.

Spiral steel pipe execution standards: Commonly used standards for spiral steel pipes are generally divided into: HSAW (helical seam submerged arc welded steel pipes for ordinary fluid transportation pipelines), API-5L (American Petroleum Institute, also called pipeline steel pipes); which are divided into two categories: PSL1 and PSL2 grade), ASTM (spiral welded steel pipe for piles).

HSAW is a general standard spiral steel pipe

API 5L spiral pipe, oil and gas industry transportation steel pipe, grade B

Generally, spiral seam high-frequency welded steel pipes for low-pressure fluid transportation are made of hot-rolled steel strip coils as pipe blanks, which are often heated and spirally formed. They are welded by high-frequency lap welding methods for general spiral seam high-frequency welded steel pipes for low-pressure fluid transportation.

Spiral welded steel pipes for piles are made of hot-rolled steel strip coils as tube blanks, which are often heated and spirally formed, and are made by double-sided submerged arc welding or high-frequency welding. They are used for steel pipes for foundation piles in civil construction structures, docks, bridges, etc.

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9 working principles of 3lpe coated steel pipe:

1. Pipeline anti-corrosion usually uses two main methods: outer coating and cathodic protection.
2. Although most of the surface of the pipeline is covered by the coating, a slight leak will cause unimaginable corrosion rates, or even holes or cracks. Therefore, in pipeline anti-corrosion, coating systems and cathodic protection are usually used together to achieve 100% coverage to avoid unimaginable consequences in the future.
3. Cathodic protection used for pipeline anti-corrosion is divided into sacrificial cathodic protection and impressed current cathodic protection.

4.lPE coated steel pipe anti-corrosion coating is used to form a continuous covering layer of insulating material to directly insulate the metal from the electrolyte in direct contact with it, so that the correct electrolytic reaction cannot occur.

5. Discontinuity points during the coating laying process are called leakage points. The main reason is caused by coating, transportation or installation process. It may also be caused by coating aging, soil stress or pipe movement in the soil. There is no Discover the damage caused by three parties in a timely manner.
6. Principle of impressed current cathodic protection: By applying an amplitude current to the protective metal, when the potential of all cathode points reaches the open circuit potential of the active anode point through cathodic polarization, the corrosion on the structure stops.
7. Components of impressed current cathodic protection: rectifier and potentiostat
8. Rectifier: Converts alternating current into direct current.

9.3LPE anti-corrosion steel pipe potentiostat: an electronic instrument that can automatically control the pipeline potential to be constant.