Steel pipe derusting methods:
Mainly use tools such as steel wire brush for surface grinding; it can remove loose or cock of oxide skin, rust, welding slag etc. the effect of Manual tools can achieve Sa3 level, and derusting power tool can achieve Sa3 level. If the oxidized scale adherent firmly reach derusting steel surface, and the effect of tools derusting is not ideal, then it can not meet the anti-corrosive coating steel pipe construction requirements of the anchor grain depth pickling.
Generally use chemical and electrochemical two methods to do pickling, but pipeline corrosion protection only uses chemical pickling. They can remove oxide skin, rust, old coating, and sometimes can be used as retreatment after blast cleaning
Although chemical cleaning can to some extent make the surface clean and rough, its anchor lines are shallow, and this method easily cause environmental pollution.
Spray (cast) shoot derusting
Spray (cast) shoot derusting, which is driven by high power electric jet with spray (cast) shoot blades to do high speed rotating, processes steel surface with abrasive like steel grit, steel shot, wire section, and minerals under the action of the centrifugal force .it not only can thoroughly remove rust, oxides and dirt, but also, under the hurl and friction of abrasive, structural steel pipe can still achieve uniform roughness needed. Spray (cast) shot, not only can expand after derusting physical adsorption of pipe surface, but also can enhance the mechanical adhesion between coating and pipe surface.
Therefore, spray (cast) shoot derusting is the ideal way for anticorrosion derusting. Generally speaking, shot peening (arenaceous) is mainly used for inner surface treatment, and peen-forming (arenaceous) derusting is for pipe outer surface treatment.