Anti-corrosion work within steel pipes is critical to ensuring the long-term service life and performance of the pipes. Steel pipes (such as carbon steel pipes) are susceptible to corrosion during use, so measures need to be taken to prevent this from happening. The following are general steps on how to protect steel pipes from internal corrosion:
1. Preparation
Before carrying out internal anti-corrosion of steel pipes, preparation work must first be carried out. This involves cleaning the inside of the pipes to ensure there are no impurities or dirt in them. We will use gas or water to flush the inside of the pipes to ensure they are clean.
2. Choose appropriate anti-corrosion materials
It is important to choose anti-corrosion materials that are suitable for the specific pipe and environment. Common anti-corrosion coatings include epoxy resin, polyurethane, polyethylene and asphalt. When selecting anti-corrosion materials, factors such as the purpose, medium, temperature, and pressure of the pipeline should be considered.
3. Painting construction
Apply the selected anti-corrosion material evenly to the inside of the pipe. This can be done by brushing, rolling or spraying. Ensure that the coating is evenly distributed and the coating thickness meets specification requirements.
4. Drying and solidification
After applying anti-corrosion paint, it needs to be allowed enough time to dry and cure. This time depends on the type and thickness of the anti-corrosion material used. During this period, the pipeline should be kept dry to prevent the anti-corrosion materials from getting damp.
5. Maintenance and monitoring
The internal anti-corrosion work of steel pipes is not a one-time job, but requires regular maintenance and monitoring. Regularly inspect the anti-corrosion coating on the inside of your pipes for wear, corrosion or other damage and whether it needs repair or renewal.
Advantages of pipe inner coating:
From the current point of view, the use of internal coating technology for pipelines has the following advantages:
(1) Reduce friction within the pipeline, improve its own performance, improve the fluidity of the pipeline, and improve its working efficiency. At present, most relevant foreign personnel believe that the surface roughness of some typical coated steel pipes is 6.4 μm, while the inner surface roughness of new steel pipes is generally 19.1 μm, and the inner surface roughness of bare pipes is 45 μm. When the roughness is below 90%, the pipe friction coefficient will be reduced by up to 33%. At this time, the number of pipes will increase accordingly.
(2) As the friction coefficient of inner-coated pipelines continues to decrease, the pressure difference between boosting stations can be reduced, the distance between stations can be expanded, and the number of boosting stations can be reduced.
(3) Save pipeline materials and construction costs. Since the roughness of the inner wall of the pipe is reduced after coating, the hydraulic friction is also constantly changing. In this way, when the gas transmission volume reaches a certain level, other conditions remain unchanged, and the designed pipe diameter can be adjusted, which can save a lot of pipeline costs and achieve the corresponding purpose.
