Pipe External Corrosion

Pipe external corrosion

1, Single FBE corrosion (FBE) Single-layerFBE Coating Epoxy powder layer because of its excellent corrosion resistance,insulation resistance and long service life and become an advanced anti-corrosion coating of the outer pipe. Sub-ordinary nature (thickness: 300 ~ 400um) andenhanced (thickness: 400 ~ 500um) two kinds.

2, Double FBE corrosion (2FBE)

Double epoxy powder coated outer coating is a composite structure,consisting of anti-corrosion epoxy powder primer and epoxy powder resistant tome chanical damage the surface layer of a coating film is completed. Normal sex(thickness ≥ 620um); enhanced (thickness ≥ 800um)

3, Two polyethylene / polypropylene anticorrosion (2PE/2PP)

Two polyethylene / polypropylene layer with good corrosion resistance,insulation resistance, long service life and resistance to mechanical damage. Sub-normal and enhanced thickness according to pipe size varies: Common Min1.8mm; enhanced minimum 2.5mm.

4, Three layer polyethylene / polypropylene anticorrosion (3PE/3PP)

Three layer polyethylene / polypropylene layer with excellent corrosion resistance, insulation resistance, longer service life and a certain degree of resistance to mechanical damage of the coating has been widely used in various large-scale projects of the corrosion in the pipeline. Common type and strengthened type two, thickness of the pipe size varies: Common minimum thickness 1.8mm; enhanced minimum thickness of 2.5mm.

3PE Anti-corrosion coating Production Flow Chart

Polyethylene three layer anti-corrosion coating, know as 3PE coating, is the world advanced anti-corrosion technology. 

3PE coating includes three layers:

1. Epoxy Primer Coating. Directly coated at the pipe surface. The thickness ranges from 60um to 80um. Ensure the overall coating has good adhesion at higher temperatures.
2. Copolymer adhesive. Mian componenet for this layer is polyolefin. The thickness of the adhesive is ranges from 170um to 250um. To make sure the top anti-corrosion coating is adhesived at the primer coating and also the pipe surface.
3. Anti-corrosion Coating (PE). The top layer is extruded polyethylene, the thickness of this lalyer is about 2mm. The total thickness of the 3PE coating is greater than 2.2~2.9mm.

3PE coating combines the excellent porperties of epoxy coating and extrusion coating of polyethylene in two. The interface properties of epoxy coatings and chemical resistance, the mechanical protection characteristics of extruded polyethylene coating combine to significantly improve the total performance of 3PE. Therefore, as buried pipelines external coating, 3PE have the most competitive advantages than other type of external coatng.

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Anti-corrosion Coating for Steel Pipe

Nowadays, anti-corrosion coated steel pipe is widely used in urban underground pipe network for transporting gas, oil, water, etc. Since the pipeline need to be buried in the soil for a quite long time, so it requires water resistance, chemical resistance and other long-term corrosion resistance. Besides, anti-corrosion coated steel pipe should meet a variety of performance to make sure the pipeline could be transport, storage and embedded in the process. For example, the pipeline should meet a specific properties such as impact resistance, abrasion resistance, compressive strength, hardness, corrosion resistance, ductility, elongation strength. The importance of these properties varies by the use of different environments, construction methods and material differences. 

Polyethylene tape coating:

Polyethylene tape is one of the main anti-corrosion mateiral widely used on pipeline. The using temperature ranges from -30 degrees to 70 degrees and it has good impact resistanc, static pressure, water tightness and other properties. The coating process is simple, convenient, affordable, so it is widely accepted by the users. When using polyethylene tape as anti-corrosion coating, the different thickness and different width of the tape is depending on the anti-corrosion requirements and different construction methods. 

Epoxy powder coating:
Epoxy powder caoting is appread in the 1960s, it is applied by electrostatic spraying method. The powder is spraded onto the pre-heated tube surface, and then a dense layer coating formed after the tube cool down. The advantages for this type of coating is have good corrosion resistance, less environmenetal pollution, wide using temperature range ( ranges from 60 degrees to 100 degrees), large tube adhesion, impact resistance, less welding damage, water resistance, electrical insulation etc. While the disadvantages are vulnerable to inquiry, high technical requirements, complex equipment needed. Therefore, it is very difficult to manage the construction filed. Different manufacturers, or even different batches of product performance differences. We advise the purchasers, when they make the desicion, their choice should focus on its mechanical properties and adhesion resistance.

The using time for buried pipeline is critical. So far, PE anti-corrotion coating is considered to be the most advanced coating in the world due to its chemical stability, mechanical resistance, scratch resistance etc.