Do steam pipes need to be painted?
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Our company requires that the surface of steam pipes be coated with high-temperature resistant paint before insulation is applied. But I saw that the steam pipes in other units are not painted; they are insulated directly, as the pipe surface does not rust at high temperatures. Should steam pipes be painted or not?
For steam pipes, two coats of red lead primer or iron oxide primer are generally applied. At high temperatures, these primers transform into a layer with strong adhesion, which acts as a barrier against moisture or other impurities that may be present in the insulation material, thereby providing some level of corrosion protection. Using high-temperature resistant anti-corrosion materials for anti-corrosion purposes is too costly, and its effectiveness is not very significant; it can be employed only when strict requirements exist.
For corrosion protection and insulation, it depends on the material of the pipe: stainless steel pipes do not require painting for corrosion protection, while other types of pipes need to be painted before being insulated
Steam pipes are of course made of carbon steel or chromium-molybdenum steel; stainless steel is not used for them.
Insulation can be applied without painting; of course, applying a coat of primer is also an option
Steam pipes must be coated with a primer before insulation is applied; otherwise, their service life will not reach the designed duration.
I’m fairly in favor of applying a primer; we used to do that as well.
What harm could occur if no primer is applied after the steam is put into use? Is there a risk of corrosion?
I agree with what was said on the first floor! Look at the actual situation! :victory:
It’s best to apply a primer first. What kind of pipes can maintain high temperatures all the time? There must be times when they stop operating, right?
Start by saving money; no painting needed. After insulating, apply another layer of red paint.
Don’t use it, but use it with insulation material!
In the atmospheric environment, especially in the polluted areas around factories today, the concentration of corrosive substances such as hydrogen sulfide is high. If it is a heating pipeline in winter, after the heating season ends, some rainwater will accumulate at the junctions between the pipeline and the supports, leading to wet hydrogen sulfide corrosion. This situation is very serious.
Insulation is feasible after applying the primer. If a primer is not applied, when the insulation is damaged and rainwater enters, it will vaporize at high temperatures, causing corrosion of the pipelines. Especially in chemical plants where there is a lot of acidic gas, corrosion protection is particularly important.