Anti-corrosion measures for steel structures in urea plant environments
Thread Content
Recently, it is necessary to carry out anti-corrosion maintenance on the steel structure of the belt bridge in the unit’s urea production facility. At present, the steel structure of the entire bridge is severely corroded; the anti-corrosion measures used at the time of construction were two coats of epoxy red lead paint followed by two coats of epoxy topcoat. Due to the high height of the pier, maintenance is somewhat more difficult; therefore, enhanced anti-corrosion measures are intended to extend its service life and reduce the frequency of future maintenance. I hope everyone can share their own experiences and methods. . . Let’s exchange ideas. . . . This post was last edited by vanroland on 2009-3-24 20:45]
If the pier can be removed relatively easily, it is recommended to remove it first and then sandblast it to remove rust. After that, apply 1 coat of zinc-rich epoxy paint with a thickness of 60 microns; 2 coats of iron oxide epoxy intermediate paint with a thickness of 120–150 microns; and finally, 2 coats of epoxy polyamide topcoat for indoor use, or acrylic polyurethane topcoat for outdoor use, each with a thickness of 80 microns. It’s done; normally, 10 years is no problem. If it is not convenient to remove the material and perform sandblasting, then mechanical grinding for rust removal is the only option, although this too needs to achieve St 3 grade ； Then, 1 coat of epoxy ferrochrome primer, 60 microns thick; 2 coats of epoxy ferrochrome intermediate coat, 120–150 microns thick; and 2 coats of epoxy polyamide topcoat (for indoor use) or acrylic polyurethane topcoat (for outdoor use), 80 microns thick each. It’s done; normally, 6-8 years should be no problem.
If the trestle can be removed relatively easily, it is recommended to remove it first and then carry out sandblasting for rust removal. After that, apply 1 coat of zinc-rich epoxy paint with a thickness of 80 microns; 2 coats of epoxy ferrochrome intermediate paint with a thickness of 120–150 microns; and 2 coats of epoxy flake paint with a thickness of 140–180 microns. Normal 10 years
Thank you for the suggestions from the two people above. What are the approximate costs for these two options (unit price)?
I agree with both options. As a supplementary note, \"if it’s not feasible to remove the rust by disassembly or sandblasting, then mechanical grinding will be the only option, but the rust removal must still achieve St 3 standard.\" It’s difficult to ensure proper control in the actual field; therefore, it is recommended that after mechanical grinding for rust removal: 1 coat of epoxy primer, 100 microns thick (a special repair epoxy coating that can safely convert some of the more difficult-to-remove rust spots into a stable paint film); 2 coats of epoxy ferrochrome intermediate coat, 120–150 microns thick; 3 coats of epoxy polyamide topcoat (for indoor use) or acrylic polyurethane topcoat (for outdoor use), 80 microns thick each. This is provided for reference only