Epoxy coal asphalt anticorrosive steel pipe is a pipe with epoxy coal asphalt coating as the anticorrosive layer, and the epoxy coal asphalt coating is composed of epoxy resin, coal tar asphalt, curing agent and filler. This coating was developed in 1955 and is mainly suitable for underwater pipes and metal structures. The coating is resistant to mineral oil and chemical agents, and the film is not only wear-resistant, but also has a good adhesion to the metal surface.

The cold coating process of epoxy coal asphalt has great advantages over hot coated petroleum asphalt and coal tar asphalt, especially in urban pipelines, which reduces urban air pollution. At present, it is widely used in urban water supply, gas and hydraulic gates, and it is also used in oil and gas pipelines. The use of epoxy coal asphalt combined with cathodic protection in Shanghai Baosteel water diversion project and Tianjin Petrochemical water supply project is good. However, epoxy coal asphalt also has its own shortcomings, mainly the construction conditions are higher, the surface must be sandblasted rust removal, there are requirements for temperature and humidity, the curing time is longer, and the construction site is required to be larger. Due to the volatilization of solvent, the pinhole rate is higher.

Epoxy coal asphalt anticorrosive steel pipe in three cloth five oil anticorrosive steel pipe is a kind of epoxy coal asphalt steel pipe, mainly made of epoxy resin + coal tar asphalt + filler coating on the surface of the steel pipe with glass cloth as a strengthening coating of the anticorrosive layer.

Three cloth five oil anticorrosion process:

Base treatment - - primer - brush over - paste cloth - two brushes - two brushes - three brushes - four brushes - check and supplement.

Note:

1. The time to apply the cloth can be carried out after the paint is dry, or it can be applied immediately after the paint is painted. Should be treated according to the specific paint.

2. The brushing interval time should be adjusted according to the drying time of the seasoning, and the drying time of various coatings is different.

3. The direction of each brushing should be perpendicular to the direction of the last brushing, and also cross brushing.

Advantages of epoxy coal asphalt anticorrosive steel pipe:

1. The anti-corrosion layer has stable performance and long service life.

2. The construction is more convenient, the coating is naturally cured, no heating equipment is required, and can be mechanized, semi-mechanized or manual construction.

3, the coating cost is low, epoxy coal asphalt under the same rust removal conditions, its comprehensive cost (including transportation, processing, loss, etc.) is lower than all anti-corrosion materials, comparable to petroleum asphalt.

4. After more than 20 years of experience accumulation, the petroleum sector has formally formulated a set of technical standards for epoxy coal leaching from design to construction, indicating that its technology is mature and reliable.

Shortcomings of epoxy coal asphalt anticorrosive steel pipe:

1. The curing reaction of the coating is affected by temperature, and the curing is slow at low temperature (below 10℃), and the construction is limited in northern winter.

2. At present, the coating manufacturers are all over the world, and low-quality products impact the market, damaging the image of epoxy coal asphalt and affecting the quality of the project.

3. Due to the need to add a small amount of solvent in the construction, it is easy to provide some construction units with the opportunity to cut corners (more solvent diluting paint cost is low).

4. Because it is a two-component, the ratio of curing agent during site construction is not allowed or uneven mixing is often not good curing or uneven quality after curing.

5. Glass cloth is used in the coating, and the glass cloth contains wax, which affects the adhesion between layers.