旧防腐层的处理。旧防腐层清除方法可采用工具撬剥离及动力工具清除或结合其

Treatment of the old anticorrosion layer. The old anticorrosion layer removal method can be carried out by tool prying and power tool removal or in combination with other methods. There should be no obvious old coating residue on the surface after removal, and damage to the metal of the pipe body should be avoided during the removal process. Lay plastic film on the bottom of the operation pit. The old anti-corrosion layer removed shall not be discarded on site, and shall be collected and handled in accordance with environmental protection requirements. Non-destructive testing remake. Detection methods include radiographic and ultrasonic detection. Anti-corrosion layer construction. Surface treatment. Epoxy coating requires sandblasting to remove rust on the surface of the steel pipe, metal surface requires sandblasting to Sa2.5 level, anchor pattern depth is 40 ~ 100μm; the treated surface should be removed by dry air blowing or cleaning brush Dust or residue. Lay plastic film at the bottom of the operation pit to collect sand and impurities. Epoxy coating construction. The solvent-free liquid epoxy coating is used for the repair of the anticorrosion layer (the total thickness of the dry film should be ≥0.8mm). The ambient temperature should be greater than 15 ° C. The use of epoxy coating should be carried out in strict accordance with the supplier's operating instructions, and the overall performance of the epoxy anti-corrosion layer after construction should meet all the requirements of the B document. Lay a plastic film at the bottom of the operation pit to collect and process the waste liquid.

Treatment of the old anti-corrosion layer. The old anti-corrosion layer removal method can be carried out by means of tool pry peeling and power tool removal or in combination with other methods. The surface after removal should be free of obvious old coating residues, and damage to tube metal should be avoided during the removal process. The bottom of the operation pit is laid with plastic film, the old anti-corrosion layer removed shall not be disposed of on-site, should be collected and in accordance with environmental protection requirements unified treatment. Non-destructive test reshoot. Detection methods include ray and ultrasonic testing. Anti-corrosion layer construction. Surface treatment. The epoxy coating requires blasting and rust removal on the steel pipe surface, the metal surface requires blasting to Sa2.5 level, anchor ingenuity of 40 to 100 m, and the treated surface should be cleaned with dry air blowing or cleaning brush to remove dust or residues from the surface. The bottom of the operating pit is covered with a plastic film to collect sand and impurities. Epoxy coating construction. Anti-corrosion layer repair using a solvent-free liquid epoxy coating (the total thickness of the dry film should be .8mm). The ambient temperature should be greater than 15 degrees C. The use of epoxy coating should be carried out in strict accordance with the supplier's operating instructions, after construction the overall performance of the epoxy anti-corrosion layer should meet all the requirements of the B document. The bottom of the operating pit is covered with plastic film to collect and treat the waste liquid.

Treatment of old anticorrosive coating. The old anticorrosive coating can be removed by means of tool prying, power tool removal or other methods. The cleaned surface shall be free of obvious old coating residues, and the metal of the pipe body shall be avoided to be damaged during the cleaning process. Plastic film shall be laid at the bottom of the operation pit. The old anti-corrosion coating removed shall not be discarded on site, and shall be collected and disposed in accordance with the environmental protection requirements. Non destructive testing. Detection methods include ray and ultrasonic detection. Construction of anticorrosive coating. Surface treatment. The surface of steel pipe shall be sand blasted for rust removal as required by epoxy coating, and the metal surface shall be sand blasted to Sa2.5 Grade, the depth of anchor grain is 40-100 μ m; the treated surface shall be cleaned with dry air or cleaning brush to remove the dust or residue on the surface. Lay plastic film at the bottom of operation pit to collect sand and impurities. Epoxy coating construction. The solvent-free liquid epoxy coating shall be selected for the repair of the anticorrosive coating (the total thickness of the dry film shall be ≥ 0.8mm ）。 The ambient temperature shall be higher than 15 ℃. The use of epoxy coating shall be in strict accordance with the operation instructions of the supplier, and the overall performance of the epoxy coating after construction shall meet all requirements of document B. Plastic film is laid at the bottom of the operation pit to collect and treat the waste liquid.