The anti-corrosion of buried steel pipes is a key procedure to ensure and prolong its service life. To ensure that the anti-corrosion insulation layer is firmly combined with the pipe wall, rust removal of the pipe is the most important. Generally, the rust on the surface of the steel pipe can be divided into floating rust, medium rust, and heavy rust according to the factory time, storage and transportation conditions, and the degree of humidity.

Floating rust: Generally, when the factory gate is short and stored outside the open air, there is only a small amount of thin crust on the surface of the pipe. The metallic luster can be exposed by manual operations such as wire brush, sandpaper, and cotton yarn.

Medium rust and heavy rust: When the delivery date is long and it is stored in the open air or repeatedly transported and the transportation is long, the surface of the pipe will appear oxidized and rusted, and the rust spots will be heavier, and the oxide scale will fall off in severe cases.

Severely corroded pipes are not suitable for sub-water delivery systems. For medium-rust pipes and large batches, mechanical derusting can be carried out using rust removers or mechanical sandblasting methods, which can improve labor efficiency and reduce pollution to people and air.

High anti-corrosion quality is required or the inner and outer walls of the pipe have been rusted, chemical rust removal methods can be used to effectively remove oxides on the inner and outer surfaces of the pipe. No matter which method is used to remove rust, the anti-corrosion layer should be treated immediately after rust removal to avoid oxidation and corrosion by air again.