For equipment with stainless steel pressure vessels and carbon steel footings, is it better to pickle the stainless steel part first, or to remove rust and paint the carbon steel part first?
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As the title suggests, I would like to ask which approach is better! Thank you :)
The standard practice is to first remove rust from the carbon steel skirt and apply an undercoat, then pickling the stainless steel part; before leaving the factory, a phenolic topcoat is applied to the carbon steel skirt.
Should the inside and outside of the skirt seat be painted, or is it enough to paint only the outside?
The skirt base is first sandblasted to remove rust and coated with an undercoat; thereafter it is welded to the container. After the container passes the hydrostatic test, it is pickled and passivated
Both the inside and outside of the skirt seat need to be painted.
There is a saying that the inside does not need to be brushed. The reason is that it’s generally not visible whether coating has been applied on the inside, and corrosion hardly occurs there; even if corrosion does happen, the design takes into account a 2mm margin against corrosion…………
Obviously, the supervisor and the owner do not accept this claim. If they are to sign for acceptance, neither the internal nor the external processing steps can be skipped.