Anti-corrosion Knowledge of Underground Steel Pipes

Time:2020/04/04 10:30:00 Browse:474

Pipeline perforation and damage often occur. At this time, pipeline anticorrosion needs to be done in advance. Pipeline anticorrosion can extend the service life of the pipeline, ensure safe production and save money. So do you know the process and advantages of pipeline anticorrosion? When it comes to anticorrosion, we must first understand the pipeline corrosion process in order to better cope with it.

1. Pipeline corrosion process

(1) The process of electrochemical dissolution and corrosion. Soil is a complex mixture of solid, liquid and gaseous three-phase materials. The solid skeleton composed of soil particles is filled with air, water and different salts. There is water and salts that can conduct ionic conduction in the soil, which makes the soil have the characteristics of an electrolyte solution and constitute an electrochemical dissolution.
      (2) Due to the influence of external leakage, stray current passes through the soil and stray current corrosion occurs.
      (3) Biological corrosion occurs due to bacterial action in the soil.
      The quality of the coating construction has a great impact on the performance of the coating. In the actual coating process, there are many examples of failure to achieve the expected anti-corrosion effect due to improper construction methods. In particular, many excellent anticorrosive coatings are extremely sensitive to the construction method. Only by strictly following their respective construction conditions can a normal coating be formed to achieve the desired anticorrosive protection.

2. What are the requirements for anticorrosive coatings?

(1) As the anticorrosive coating of underground pipelines is not easy to repair, in order to ensure the operating life of the pipeline, the anticorrosive life of the anticorrosive coating should be long.
      (2) The selected coatings should have excellent rust resistance, permeability resistance and moisture resistance. Considering that the pipeline may pass through contaminated soil or river, the coating should also have excellent chemical resistance.
      (3) The anticorrosive coating should be resistant to penetration by plant root diameter.
      (4) Considering the equipment and transfer needs, the coating should have good abrasion resistance, abrasion resistance and solidity.
      (5) The anti-corrosion layer must be able to effectively resist the stress caused by soil; the anti-corrosion layer needs to have certain toughness to effectively prevent cracking; 

3. Pipeline anticorrosive steps

The anti-corrosion of steel pipes is epoxy glass coal-coated glass fiber cloth with epoxy coal tar paint according to the requirements of the drawing. → Topcoat → Topcoat;
      Construction process of inner wall: rust removal of the pipe → primer coating → first coat of top coat → second coat of top coat → third coat of top coat
      At the same time, the anti-corrosion coating thickness of pipeline must be continuously measured by the anti-corrosion painting thickness meter to ensure the best anti-corrosion effect.

4. Advantages of anti-corrosion steel pipes in practical applications

(1) Longer life, ordinary steel pipe has a certain life. After anti-corrosion treatment of ordinary materials, its life can be up to 20-30 years or longer. 
      (2) The construction is simple and the steps are fast. The construction can be carried out on the factory and the site. 
      (3) Anti-corrosion steel pipe with environmental protection as the design idea. Today, when it comes to environmental protection, this design is more in line with the needs of the times. 
      (4) Coating thickness inspection of anticorrosive pipelines
       For the measurement of the coating thickness of anticorrosive pipes, it is recommended to use Linshang Technology LS223 painting thickness metesr. This painting thickness meter uses the principle of eddy current and Hall effect measurement principles to accurately measure the non-magnetic coating thickness on magnetic metals and the non-conductive coating thickness on non-magnetic metal substrates. LS223 painting thickness meter can be widely used in the shipbuilding industry, hardware, metal processing industry coatings and anti-corrosion coating thickness measurement. The LS223 painting thickness meter adopts the separate design and can view the data while measuring in a complex environment. The painting thickness meter can accurately and non-destructively measure the coating thickness, which can be used in engineering sites and laboratories.
      The above is the relevant introduction of anticorrosion of underground steel pipes. In the future, pipeline construction will be the main force.