General ventilation engineering and air conditioning engineering are inseparable from the opening of the air duct, and there are many strict requirements for the anticorrosion or color of the project, which requires anti-corrosion coating or paint. Precautions for painting of ventilation duct system are as follows:
1. The paint number used must meet the design requirements or construction quality inspection standards, and have the product factory certificate. It is necessary to use the paint within the useful period. If it has exceeded the regular time, it should be sent to the skill inspection part for identification, and it can be used only after it is recognized as qualified. If because the storage is not good, even in the useful period, but there is a significant transformation, also can not be used.
2. Before coating, check whether the surface treatment of pipeline or equipment meets the requirements. It is necessary to dry the surface of ventilation pipes or equipment thoroughly before painting.
3. The environmental humidity of painting should not be too low or the relative humidity should not be too high, otherwise the evaporation time of the paint will be too long, which will affect the anti-corrosion performance. When painting, it is necessary to master the environmental conditions. Generally, the ambient humidity should not be lower than 5 ℃, and the humidity should be lower than 85%.
4. In order to ensure that the thickness of the film is uniform and there is no leakage, blistering and foaming at the bottom after coating, the consistency of the film should not be too large or too small. If the thickness is too large, it will not only spoil the coating, but also cause the phenomenon of falling and coiling; if the thickness is too small, the coating will be missed, bubbling and foaming at the bottom.
5. In order to make the paint film and the paint film firm, it is necessary to compare with the first antirust paint completely dry before painting twice, otherwise the paint layer will drop.
6. The anticorrosion operation of steel plate air duct generally adopts two ways: before production and after production. Before the wind, the production pipe should be coated with antirust primer in advance. Its advantage is that the quality of the paint brush does not miss the coating phenomenon. It can extend the service life of the air duct, and the subsequent data will not rust in a short time, so it can be recovered. The air duct paint after production is painted. In the process of manufacturing air duct, it is necessary to apply anti rust primer on the bite of steel plate.
7. After the reinforcement of pipe flange or angle steel, it should be installed with Xuchang ventilation pipeline before applying anti rust primer. After installation, it is not allowed to apply anti rust primer, otherwise, the reinforcement of flange or angle steel and the touch surface of pipe will cover the anti rust primer, which will lead to corrosion.
8. Before installation, the blade and body of air outlet and air valve should be coated with anti rust primer according to the process conditions to avoid coating leakage. If the installation is coated with anti-corrosion primer, the leakage of some positions will be formed and corrosion will occur.
9. It is necessary to carry out anti-corrosion work of pipe support, crane and support after prefabrication. Piping should be avoided from being lifted onto supports and then painted, which will allow the support sections, cranes, supports and piping to touch the leaking coating.
10. The physical and chemical properties of all kinds of paints used should be understood, and the operation should be carried out according to the technical safety conditions, so as to avoid the occurrence of incidents.