Brief introduction to coating process of anticorrosive coating for conveying pipe-3

The thickness of coating film shall be measured after each coating is dry The total thickness shall be measured after the completion of the whole coating system More than 90% of the measuring points must reach the specified value If the film thickness does not reach the specified value, it shall not be less than 90% of the specified value, otherwise, it shall be coated or added with a value This system has been widely used in underground water and gas pipeline projects in Shanghai, Hunan and Shantou, Guangdong for 15 years, and is still in normal use At present, 5 pipelines in China are operated with domestic coal tar enamel paint, and the quality of anticorrosive pipeline fully meets the requirements of SY / t0079-93 standard Coal tar enamel is made of coal tar pitch, coal powder, anthracene oil and mineral filler by boiling Its formula is: coal tar pitch 20% ~ 35% anthracene oil 25% ~ 35% coal powder 20% ~ 30% mineral filler 25% ~ 40% should pay attention to dehydration, the whole process needs 10 ~ 12h Lu Weizhong introduced the application of anti-corrosion technology in the water supply pipeline system, and also mentioned that the anti-corrosion coating for the outer wall of the pipeline includes petroleum asphalt, coal tar pitch celadon paint, adhesive tape, extruded polyethylene, epoxy asphalt and fusion bonded epoxy Extruded polyethylene is easy to produce stress cracking if it is coated on large-diameter pipes with a diameter of more than 508mm (20 inches) The inner wall corrosion of water supply pipeline is more serious than the outer wall (mainly corrosion) In the late 1980s in China, fusion bonded powder coatings were produced from abroad The corrosion Institute of Chinese Academy of Sciences has developed fusion bonded epoxy powder (SEBF) and solventless high performance composite liquid epoxy coating (SLF) since 1990s, which has excellent corrosion resistance