With the sustained economic development in our country, the government has made great efforts to develop the energy industry and long-distance oil and gas pipelines are important ways to ensure energy supply. During the anticorrosive construction of pipeline (gas) pipeline, the pipe surface treatment is the key factor that determines the anti-corrosion service life of pipelines First, it is a prerequisite for the coating and pipe can be firmly combined. The research institutes have verified that the life of the coating depends on the type of coating, coating quality and construction environment and other factors, the impact of the surface treatment of steel pipe coating life expectancy of about 50%, therefore, it should be strictly in accordance with the coating standard. Steel pipe surface requirements, and continue to explore and summarize the continuous improvement of steel pipe surface treatment methods.
1, Cleaning
The use of solvent, emulsion cleaning steel surface, in order to achieve the removal of oil, grease, dust, lubricants and similar organic matter, but it can not remove the rust on the steel surface, scale, welding and so on, and therefore only as an adjunct to preservative production.
2, Tool rust
The main use of wire brush and other tools on the polished steel surface, you can remove the loose or tilt the oxide skin, rust, welding slag and so on. Manual tool rust can reach Sa2 level, power tool rust can reach Sa3 level, if the steel surface attached to the solid oxide scale, tool rust effect is not satisfactory, reaching the depth of anchor embossed construction requirements.
3, Pickling
Generally use chemical and electrolytic pickling two ways to do, pipe corrosion only chemical pickling, you can remove the scale, rust, the old coating, and sometimes can be used as a reprocessing sandblasting rust. Although chemical cleaning can make the surface to a certain degree of cleanliness and roughness, its anchor pattern shallow, and easy to cause environmental pollution.
4, Spray (throwing) shot rust
Spraying (throwing) shot rust is driven by high-power motor spray (throwing) shoot high-speed rotation of the blade, so grit, steel balls, wire segments, minerals and other abrasive centrifugal force under the action of spraying (throwing), not only can completely remove the rust, oxides and dirt, but also in the steel under the impact of abrasive and friction, but also to achieve the required uniform roughness. Spraying (throwing) shot rust, not only can expand the physical adsorption of the pipe surface, but also can enhance the coating and pipe surface mechanical adhesion. Therefore, spray (throwing) throw rust is ideal anti-corrosion pipe rust way. In general, shot peening (sand) rust is mainly used for pipe surface treatment, shot blasting (sand) rust is mainly used for pipe surface treatment.
