The purpose of anti-corrosion of seamless steel pipes for low and medium pressure boilers is to prolong the service life of the steel pipes themselves. Especially when it is used in underground industrial pipelines, oil and gas transportation, high-quality water pipelines and other projects, anti-corrosion treatment is required. Commonly used low and medium pressure boiler seamless steel pipe anti-corrosion methods are as follows.
1. 3PE anti-corrosion;
2. Epoxy coal tar anticorrosion;
3. Epoxy resin anticorrosion
4. IPN8710 anti-corrosion;
5. Anticorrosion of cement mortar.
3PE anti-corrosion process of low and medium pressure boiler steel pipe:
1. Derusting of seamless steel pipes for low and medium pressure boilers
The surface of the pipe should be cleaned of grease, ash, rust, and scale before applying primer. The quality standard of sandblasting to remove rust reaches Sa2.5 level.
2. After removing rust on the surface of the seamless steel pipe of the low and medium pressure boiler, apply primer, and the time interval between them shall not exceed 8 hours. When applying the primer, the base surface should be dry. The primer shall be applied evenly and fully without clotting or blistering. The two ends of the tube shall not be painted within the range of 150～250mm.
3. After the surface of the primer is dry, apply the topcoat and wrap the glass cloth. The time interval between the primer and the first topcoat should not exceed 24 hours.
4. Epoxy coal tar pitch paint adopts two-component, room temperature curing paint; glass fiber cloth adopts dry, dewaxed, untwisted, edge-sealing, medium alkali, and the density of warp and weft is 10*12 pieces/cm～12*12 pieces/ cm glass cloth. Wrap the glass cloth immediately after the topcoat is applied. The edge width of the glass cloth is 30-40mm, the lap length of the joint is not less than 100mm, and the lap joints of each layer are staggered. The oil penetration rate of the glass cloth is more than 95%, no gaps larger than 50mm*50mm should appear, and 150-250mm stepped stubble should be left at the pipe end.
5. The construction of the pipe joints of low and medium pressure boilers should be carried out after the welding pressure test is qualified. The new and old anti-corrosion blanks should not be less than 50mm, the joint overlap length should not be less than 100mm, and the stubble should be firmly and tightly bonded.
6. Low and medium pressure boiler seamless steel tube outer wall coating mechanism: one bottom, two sides, one cloth side, the total thickness of dry film is 400μm.
Tips: ASTM A53 pipe covers Seamless and Welded, Black and Hot-Dipped Galvanized nominal (average) wall pipe for coiling, bending, flanging and other special purposes and is suitable for welding. Continuous-Welded pipe is not intended for flanging.
1. 3PE anti-corrosion;
2. Epoxy coal tar anticorrosion;
3. Epoxy resin anticorrosion
4. IPN8710 anti-corrosion;
5. Anticorrosion of cement mortar.
3PE anti-corrosion process of low and medium pressure boiler steel pipe:
1. Derusting of seamless steel pipes for low and medium pressure boilers
The surface of the pipe should be cleaned of grease, ash, rust, and scale before applying primer. The quality standard of sandblasting to remove rust reaches Sa2.5 level.
2. After removing rust on the surface of the seamless steel pipe of the low and medium pressure boiler, apply primer, and the time interval between them shall not exceed 8 hours. When applying the primer, the base surface should be dry. The primer shall be applied evenly and fully without clotting or blistering. The two ends of the tube shall not be painted within the range of 150～250mm.
3. After the surface of the primer is dry, apply the topcoat and wrap the glass cloth. The time interval between the primer and the first topcoat should not exceed 24 hours.
4. Epoxy coal tar pitch paint adopts two-component, room temperature curing paint; glass fiber cloth adopts dry, dewaxed, untwisted, edge-sealing, medium alkali, and the density of warp and weft is 10*12 pieces/cm～12*12 pieces/ cm glass cloth. Wrap the glass cloth immediately after the topcoat is applied. The edge width of the glass cloth is 30-40mm, the lap length of the joint is not less than 100mm, and the lap joints of each layer are staggered. The oil penetration rate of the glass cloth is more than 95%, no gaps larger than 50mm*50mm should appear, and 150-250mm stepped stubble should be left at the pipe end.
5. The construction of the pipe joints of low and medium pressure boilers should be carried out after the welding pressure test is qualified. The new and old anti-corrosion blanks should not be less than 50mm, the joint overlap length should not be less than 100mm, and the stubble should be firmly and tightly bonded.
6. Low and medium pressure boiler seamless steel tube outer wall coating mechanism: one bottom, two sides, one cloth side, the total thickness of dry film is 400μm.
7.Low and medium pressure boiler seamless steel pipe inner wall coating mechanism: one bottom and three sides, the total thickness of dry film is 300μm.
Tips: ASTM A53 pipe covers Seamless and Welded, Black and Hot-Dipped Galvanized nominal (average) wall pipe for coiling, bending, flanging and other special purposes and is suitable for welding. Continuous-Welded pipe is not intended for flanging.
