I. Cleaning

　　Solvents and emulsions are used to clean the steel surface to remove oil, grease, dust, lubricants, and similar organics, but they cannot remove rust, mill scale, or welding flux, so they serve only as an auxiliary method in anti-corrosion work.

　　II. Pickling

　　Pickling is generally done by chemical and electrolytic methods. Pipeline anti-corrosion uses only chemical pickling, which can remove mill scale, rust, and old coatings, and can sometimes be used as post-treatment after abrasive blasting. Although chemical cleaning can achieve a certain degree of cleanliness and roughness, the anchor pattern is shallow and it easily causes pollution to the surrounding environment.

　　III. Tool Derusting

　　Tools such as wire brushes are mainly used to grind the steel surface, which can remove loose mill scale, rust, weld slag, etc. Manual tool derusting can reach St2, and power tool derusting can reach St3. If firmly attached iron oxide scale is present on the steel surface, tool derusting is not ideal and cannot achieve the anchor-pattern depth required for anti-corrosion construction.

　　IV. Blast Derusting

　　Abrasive blasting for rust removal is driven by a high-power motor that rotates the blasting blades at high speed, so that abrasives such as steel shot, steel grit, wire segments, and minerals are blasted onto the LSAW steel pipe surface under the motor's powerful centrifugal force. This not only thoroughly removes oxides, rust, and dirt, but also, under the violent impact and friction of the abrasives, enables the LSAW steel pipe to achieve the required uniform roughness.

　　After abrasive blasting for rust removal, not only is the physical adsorption on the pipe surface increased, but the mechanical adhesion between the anti-corrosion coating and the pipe surface is also enhanced. Therefore, abrasive blasting is an ideal rust-removal method for pipeline anti-corrosion. Generally speaking, air blasting is mainly used for inner surface treatment of pipes, and wheel blasting is mainly used for outer surface treatment of LSAW steel pipes.

　　During production, relevant technical indicators of rust removal must be strictly required to prevent secondary damage to LSAW steel pipes caused by operational errors. After derusting, the appearance of LSAW steel pipes will be smoother than before derusting. Derusting of LSAW steel pipes is a frequently used technology in the steel pipe industry.

　　The above content is by Black-Jacketed Direct-Buried LSAW Pipe compiled. For more details, please follow us https://www.sdhpgy.com