Rust removal is an important part of the pipeline anticorrosion process. At present, there are many rust removal methods, such as manual rust removal, sandblasting and pickling and so on. Among them, manual rust removal, mechanical rust removal and coating rust removal (anti-corrosion brushing oil) are relatively common rust removal methods. The following Nansteel Manufacturing Co.,Ltd will briefly introduce the specific operation requirements of these three rust removal processes.
1. Manual descaling
Use a scraper and file to remove the oxide scale and casting sand on the surface of the pipe, equipment and container, then use a wire brush to remove the rust on the surface of the pipe, equipment and container, then polish it with sandpaper, and then wipe it with cotton wool net.
2. Mechanical derusting
First use a scraper and file to remove the oxide scale and casting sand on the surface of the pipe; then one person in front of the rust remover and the other after the rust remover, put the pipe in the rust remover and repeatedly remove the rust until the metal color is exposed; brush Before oiling, wipe it again with cotton thread to remove the floating dust on the surface.
3. Anti-corrosion brushing
Pipes, equipment and container valves are generally anti-corrosive and oil-brushed according to design requirements. When there is no design requirement, they should be carried out according to the following regulations:
1). Surface-mounted pipelines, equipment and containers must be painted with one anti-rust paint first, and two top coats should be painted before handover. If heat preservation and anti-condensation requirements are required, two anti-rust paints should be painted;
2). Apply two anti-rust paints to concealed pipelines, equipment and containers. The second anti-rust paint must be applied after the first paint is dry, and the consistency of the anti-rust paint should be appropriate;
3). When the buried pipeline is used as the anticorrosive layer, if it is constructed in winter, it is advisable to use rubber solvent oil or aviation gasoline to melt 30A or 30B petroleum asphalt. The weight ratio: asphalt: gasoline = 1:2. The anti-corrosion painting method generally includes Two kinds:
① Manual painting: Manual painting should be applied in layers, each layer should be reciprocating, criss-crossed, and the coating should be uniform, and no omission or flow should be allowed;
②Mechanical spraying: The sprayed paint flow should be perpendicular to the sprayed surface during spraying. When the sprayed surface is flat, the distance between the nozzle and the sprayed surface should be 250-350mm. If the sprayed surface is an arc surface, the distance between the nozzle and the sprayed surface should be about 400mm , When spraying, the movement of the nozzle should be uniform, the speed should be maintained at 10-18m/min, and the compressed air pressure used for spraying should be 0.2-0.4MPa.
1. Manual descaling
Use a scraper and file to remove the oxide scale and casting sand on the surface of the pipe, equipment and container, then use a wire brush to remove the rust on the surface of the pipe, equipment and container, then polish it with sandpaper, and then wipe it with cotton wool net.
2. Mechanical derusting
First use a scraper and file to remove the oxide scale and casting sand on the surface of the pipe; then one person in front of the rust remover and the other after the rust remover, put the pipe in the rust remover and repeatedly remove the rust until the metal color is exposed; brush Before oiling, wipe it again with cotton thread to remove the floating dust on the surface.
3. Anti-corrosion brushing
Pipes, equipment and container valves are generally anti-corrosive and oil-brushed according to design requirements. When there is no design requirement, they should be carried out according to the following regulations:
1). Surface-mounted pipelines, equipment and containers must be painted with one anti-rust paint first, and two top coats should be painted before handover. If heat preservation and anti-condensation requirements are required, two anti-rust paints should be painted;
2). Apply two anti-rust paints to concealed pipelines, equipment and containers. The second anti-rust paint must be applied after the first paint is dry, and the consistency of the anti-rust paint should be appropriate;
3). When the buried pipeline is used as the anticorrosive layer, if it is constructed in winter, it is advisable to use rubber solvent oil or aviation gasoline to melt 30A or 30B petroleum asphalt. The weight ratio: asphalt: gasoline = 1:2. The anti-corrosion painting method generally includes Two kinds:
① Manual painting: Manual painting should be applied in layers, each layer should be reciprocating, criss-crossed, and the coating should be uniform, and no omission or flow should be allowed;
②Mechanical spraying: The sprayed paint flow should be perpendicular to the sprayed surface during spraying. When the sprayed surface is flat, the distance between the nozzle and the sprayed surface should be 250-350mm. If the sprayed surface is an arc surface, the distance between the nozzle and the sprayed surface should be about 400mm , When spraying, the movement of the nozzle should be uniform, the speed should be maintained at 10-18m/min, and the compressed air pressure used for spraying should be 0.2-0.4MPa.
