Four Common Methods for Rust Removal on Spiral Welded Steel Pipes

1. Cleaning: Utilizing solvents and emulsions to clean the surface of steel to remove oil, grease, dust, lubricants, and similar organic substances. However, it cannot eliminate rust, scale, and flux from the steel surface, thus serving only as an auxiliary method in anti-corrosion operations.

2. Pickling: Generally, pickling is done using either chemical or electrolytic methods. For pipeline anticorrosion, only chemical pickling is used, which can remove oxidation scale, rust, and old coatings. It can also be used as a post-treatment after sandblasting for rust removal.

Chemical CleaningSpiral Welded Steel PipeAlthough it can achieve certain levels of cleanliness and roughness on the surface, the anchor pattern is shallow and it is prone to causing pollution to the surrounding environment.

3. Tool Rust Removal: Primarily using wire brushes and other tools to sand the surface of steel, which can remove loose oxide scales, rust, weld slag, etc.

Manual tool rust removal can achieve Sa2 level, power tool rust removal can reach Sa3 level. If the steel surface of the spiral welded steel pipe has firmly attached iron oxide scale, the rust removal effect of the tool is not ideal, and it cannot meet the anchor pattern depth required for anticorrosive construction.

4. Shot Blasting: Shot blasting involves a high-powered motor driving a jetting blade to rotate at high speeds, propelling steel grit, steel shot, wire segments, minerals, and other abrasives against the surface of spiral-welded steel pipes under the strong centrifugal force of the motor. This not only thoroughly removes oxides, rust, and dirt but also achieves the desired uniform roughness on the spiral-welded steel pipes through the intense impact and friction of the abrasives.

After jet derusting, it not only expands the physical adsorption on the tube surface but also enhances the mechanical adhesion between the anti-corrosion coating and the tube surface. Therefore, jet derusting is the ideal method for pipeline anti-corrosion.

Generally, shot blasting is mainly used for the internal surface treatment of pipes, while sandblasting is primarily employed for the external surface treatment of spiral-welded steel pipes.

During the production process, stringent technical specifications for rust removal must be adhered to, to prevent secondary damage to spiral-welded steel pipes due to operational errors. After rust removal, the product appearance will be smoother compared to before, and rust removal is a commonly used technique in the steel pipe industry.