Regarding the painting issue of fasteners for non-standard equipment
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Everyone, I went to the factory to inspect the custom-made equipment and found that the fasteners used to secure the mating flanges of all the towers had been painted over. This shouldn’t be allowed, right?； The original bolts and nuts no longer show their original color; they have all been painted ； I was wondering if there are any national standards or regulations regarding this – such fasteners shouldn’t be painted, right? ? ? Please give me some advice! ! Thank you!
I have also come across statements saying that this is not allowed. But the corresponding construction or acceptance specifications were not taken into account.
Painting is prohibited on the flange sealing surfaces and connection bolts. However, bolt corrosion protection can be achieved by applying grease.
As the original poster said, painting bolt fasteners is an improper practice, but it has no impact on the normal operation of the equipment.
After spraying paint on bolt fasteners, it affects their disassembly and assembly.
The painting is not done properly. It should be oiled, but it cannot be oiled in the oxygen business.
Equipment fasteners generally are not allowed to be painted; to prevent corrosion, they are usually treated by blackening or phosphating. If there are no special requirements, lubricants such as molybdenum disulfide can also be applied to their surfaces.
Sometimes, it’s not just the bolts on the equipment but also those on the pipelines. For convenience, and sometimes for the sake of what is considered aesthetic appeal, the anti-corrosion team paints everything that is exposed, including the flanges and bolts. When it comes time to remove or install these bolts later, the workers get very angry at the people who handled the anti-corrosion treatment. In fact, many times the anti-corrosion workers don’t even know that this material cannot be painted; they need to be reminded and supervised by the operators
The anti-corrosion treatment of bolts needs to be considered separately based on their operating conditions. Spraying paint together with the equipment is not allowed.
1: Most bolts and nuts are treated with anti-corrosion methods such as galvanizing, bluing, and phosphating at the time of production, depending on their intended use. 2: Except in cases where painting is clearly not possible, it is not impossible to paint the assembled bolts, nor can it be avoided. 3: The corrosion protection measures applied to bolts at the factory may be compromised during assembly; the corrosion-resistant properties of paint are also effective for bolts. 4: The strength of the paint has a relatively small impact on unscrewing the bolts. Moreover, the paint layer is prone to damage. 5: Bolts that cannot be painted or require oiling for corrosion protection fall under special requirements and should be specified clearly.