How to remove rust from high-pressure boiler tubes?

High-pressure boiler tubes operate under extreme temperature and pressure conditions, making them susceptible to oxidation and corrosion from high-temperature flue gas and water vapor. This article discusses effective methods for removing rust from high-pressure boiler tubes.

1) Cleaning

Solvents and emulsions are used to remove oil, grease, dust, lubricants, and other similar organic matter from the surface. However, these cleaning agents cannot remove surface corrosion, oxide scale, or solder from high-pressure boiler steel pipes. They are only suitable as auxiliary methods in the anti-corrosion process.

2) Anti-Rust Treatment with Special Tools

Special tools, such as steel brushes, are used to remove surface damage, loose dirt, rust, and splashes from high-pressure boiler seamless steel pipes.

Hand Tools: Can achieve Sa2 level of rust removal.

Power Tools: Can achieve Sa3 level of rust removal.

However, if the surface has strong, adhered dirt, these tools may not effectively achieve the steel anchorage depth specified for FRP anti-corrosion.

3) Pickling

Chemical and electrolytic methods are generally used for pickling to remove scale, rust, and old coatings. Chemical pickling can be effective in cleaning the surface, but it tends to create a shallow anchor line and can leave the surface susceptible to contamination.

4) Anti-Rust Treatment with Sprayers

Spray anti-rust treatment involves using a high-power electrospray blade rotating at high speed. This process propels wear-resistant materials such as emery sand, bearing steel balls, stainless steel wires, and minerals onto the surface of the seamless steel pipe under centripetal force.

Effectiveness: This method not only removes rust, metal oxides, and stains but also abrades the surface to achieve the desired uniform roughness.

Spray anti-rust treatment enhances the physical adsorption and mechanical adhesion of the pipe surface, making it an ideal rust removal method for pipeline anti-corrosion. Generally, spray anti-rust treatment is primarily used for the surface treatment of high-pressure boiler steel pipes, while shot blasting is mainly used for pipe surface treatment.

Conclusion

Various rust removal methods, including cleaning, special tools, pickling, and spray anti-rust treatment, are employed to maintain the integrity of high-pressure boiler tubes. Among these, spray anti-rust treatment is particularly effective for achieving uniform surface roughness and enhancing the adhesion properties, making it a preferred method in the anti-corrosion process for high-pressure boiler tubes.