Several misunderstandings exist in the practical application of anti-corrosion coating

Anti-corrosion coatings in the petrochemical industry has a wide range of applications, in contact with some enterprises in the industry and the investigation of these enterprises found that there are several errors in the practical application of anti-corrosion coating:
1. pay attention to anti-corrosion coatings, contempt for surface treatment:
(1) anti-corrosion coating of metal or non-metallic materials Before loading, the substation surface must be pre-treated, which is a very important part of anti-corrosion coating, if the surface treatment is not proper, will directly affect the coating on the substation adhesion, coating quality and the protection of the substation performance, coating life, coating appearance, etc. , the analysis shows that the quality of surface treatment is the main factor affecting the quality of the coating.
(2) to several major petrochemical enterprises to investigate and understand, showing that the main factors affecting anti-corrosion coatings can not reach the design of anti-corrosion years are mostly surface treatment does not meet the requirements, in the material selection, matching, environmental conditions and other factors accounted for more than 50% Especially for the steel structure and the installation area of non-insulation storage tanks, reactors, pipe wall, etc. , especially, some pipe gallery steel structure and tank wall in just six months on the point erosion, less than a year began a large area of rust, flow "yellow water."
(3) the relevant personnel are only more concerned about the quality of anti-corrosion coatings, application effects and performance in the industry, ignore surface treatment requirements, and even to our basic requirements for surface treatment is attributed to anti-corrosion coating construction conditions are harsh, relatively speaking, unwilling to spend money on surface treatment, spend energy, so that the anti-corrosion protection life is bound to be greatly shortened
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2. Pay attention to material selection, despise anti-corrosion support:
(1) because of the different performance of anti-corrosion coatings, in different environmental media, coating characteristics, construction conditions and anti-corrosion design years, should make different choices, so can not simply evaluate the "good" "bad" anti-corrosion coatings, but should be used as a system to choose anti-corrosion coatings, that is, matching.
(2) Matching considerations and external factors related to the coating itself related to the coating properties, bottom, neutral and surface coating re-coating adaptive corrosion conditions, coating film/curing conditions surface treatment requirements, coating thickness coating method, anti-corrosion design age, technical and economic indicators.
(3) in the actual business, do not pay attention to anti-corrosion system supporting the situation abounds, some projects choose anti-corrosion paint is very good, according to the long-term anti-corrosion design, epoxy zinc-rich primer / epoxy paint / polyurethane finish, but the surface treatment is powered to polish only up to ST2/ST3 requirements, or even only use electric steel / copper brush to clean the surface Can not meet the long-term anti-corrosion requirements of more than 8 years; some surface treatment using sand blasting, to reach Sa2.5, primer but choose red Dan, "dress, wear grass shoes", especially maintenance works, re-coated on the old coating, regardless of the adaptability of the coating and the old coating, the appearance of bite bottom, foaming and other phenomena, resulting in the failure of the coating
3. Pay attention to the unit price of materials, despise the comprehensive cost:
(1) compared to the good performance of anti-corrosion coatings, some large manufacturers, such as AKZONOBEL company's international brand paint, Haihong old people's company's old brand paint, due to its raw material selection restrictions, product technology Content and other factors, production costs are higher, per liter (kg) price is naturally higher, but a large part of the product because it is a high solid part of the product, its rated film thickness under the coating area is higher, in the same design film thickness conditions, the comprehensive cost of anti-corrosion coating is not high, and the quality is greatly improved. Therefore, in the process of technical and economic comparison of anti-corrosion coatings, attention should also be paid to coating area and coating life.
(2) constitute anti-corrosion construction in the cost of anti-corrosion coatings many factors, summarized are: design film thickness, paint performance indicators (such as solid content), paint loss, construction methods.
(3) in the course of business dealings with users, some users often only pay attention to the unit price of materials, do not calculate the comprehensive cost, the use of small factory production of low-cost anti-corrosion paint, poor quality, low solid content, low coating area, the final total cost is not low, this kind of phenomenon is very common.
4. Pay attention to short-term investment, despise long-term costs:
(1) "anti-corrosion maintenance year after year, but different sizes", this is the author of the petrochemical industry anti-corrosion joke, the author of several large petrochemical enterprises survey: more than 70% of the installation steel structure has begun to rust for three years, five years has been on the "face is completely different", the pipe gallery steel structure five years has been rusty, non-insulation pipe line is also a similar situation.
(2) When the anti-corrosion coating system is selected, technical and economic comparison should be carried out, different projects should be set with different anti-corrosion life, to avoid the use of systems with too short life, these systems appear to have a small initial investment, but the cost of late maintenance is high, due to the complexity of maintenance, many projects in the cost of follow-up maintenance is even higher than the initial investment.
(3) after maintenance of anti-corrosion life is usually not as good as when the new use of anti-corrosion age longer coating system to good, in the total investment of petrochemical projects, anti-corrosion must compete for a smaller proportion, in order to ensure the long-term operation of the device, fully conditional selection of anti-corrosion years longer coating system, reduce the late "repair and repair", to avoid late because corrosion is not in place, affect normal production, increase maintenance input.