There is a cleaning and flushing step during maintenance for both internal and external plastic-coated steel pipes. The cleaning step is also very important. So how to implement it?
Cleaning of internal and external plastic-coated steel pipes uses solvents and emulsions to clean the steel surface to achieve the effect of removing oil, grease, dust, lubricants and similar organic substances, but it cannot remove rust, oxide scale, solder, etc. Therefore, it is only used as an auxiliary method in anti-corrosion production. Rust removal: Mainly use tools such as wire brushes to polish the steel surface to remove loose or raised oxide scale, rust, welding slag, etc.
The rust removal of hand tools can reach Sa2 level, and the rust removal of electric tools can reach Sa3 level. If there is a strong oxide scale attached to the surface of the steel, the rust removal effect of the tool will not be ideal and the depth of the anchor pattern required for anti-corrosion construction will not be achieved. Pickling: Generally, chemical and electrolytic methods are used for pickling treatment. Pipe anticorrosion uses only chemical pickling to remove scale, rust and old coatings. Sometimes it can also be used as reprocessing after sand blasting and rust removal.
Although chemical cleaning can achieve a certain degree of cleanliness and roughness on the surface, its anchor lines are shallow and can easily cause pollution to the human body. Spray (throw) rust removal: Spray (throw) rust removal is driven by a high-power motor to rotate the spray (throw) blade at high speed, so that steel sand, steel shot, iron and other abrasives are sprayed (thrown) on the surface of the plastic-coated pipe. It can completely remove rust, oxides and dirt, and the internal and external plastic-coated pipes can achieve the required uniform roughness under the action of strong abrasive impact and friction.
The adhesion between the coating and the substrate is an important indicator for evaluating the corrosion resistance of the coating. The stronger the adhesion, the better the corrosion resistance and the more durable the coating. Surface treatment completed. Epoxy coal tar primer can be applied twice to protect against moisture and rust. Use acetone or other volatile cleaners to remove oil, tar and other dirt on the surface of the gas cabinet. Clean the inside and outside of plastic-coated steel pipes. After cleaning, the surface should be dry, free of oil and dirt.
