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Corrosion Policy Decision Making


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surface. A noteworthy point about carbon steel samples prepared with copper slags was that their particles trapped in all samples. Slag particles were observed which could not washed out even by using air pressure (five bar pressure) and washing with solvent. However, for samples prepared with silica sand, leaving excess particles from the surface with compressed air were easily and completely removed from the surface. All samples were coated with the same paint layer with a similar dry film thickness.

Test Standard Result for all samples
Hardness (mohz) SSPC‐AB‐1 At least 6
Weight change on ignition SSPC‐AB‐1 Max. 5%
Oil content ASTM D‐7393 No visible
Specific gravity ASTM C‐128 Min. 2.5
Moisture content ASTM C‐566 0.5%<
Water soluble contaminants ASTM D‐4940 <1000 μs/cm
Abrasives Adhesion test before exposureASTM D4541Psia Adhesion test; 1500 hours salt spray and 24 hours dryingASTM D4541 Psia Adhesion test; 1500 hours humidity and24 hours dryingASTM D4541Psia
Copper slag Sample A 1687 528 1603
Copper slag Sample B 1541 486 Test error
Copper slag Sample C 1569 388 1160
Copper slag Sample D 1446 516 1223
Cupper slag Sample E 1355 422 1306
Supper slag Sample F 1525 1329 1385
Silica sand Sample G 1687 1855 989
Silica sand Sample H 1900 1917 1898

      2.2.5.8 Technical Painting Operations

Photo depicts some examples of paint application problems. Rusting on primer due to thin primer layer (a). Running of paint and settling of dirt due to adjacent blasting operation (b).

      Many paint defects are mainly related to the method of their application. The wrong choice of hardener and thinner for paints, incorrect mixing of paint components, and wrong choice of different layers of a paint system are the most common causes of complication in paint application. Accuracy at the important points in the catalog can cut problems. Lifting, orange peel, overspray, pinholes, spatter coat, etc. are some of the complications that may occur due to these problems [7].

      Excessive hot or cold temperature of the substrate, high humidity, dust, and local pollution are other factors that may cause complications during paint application. Adherence to implementation instructions greatly reduces these problems. Complications such as amine blushing, blushing, holidays, rusting, etc. are observed in these conditions [7].

      2.2.5.9 Inspection and Management

      On the other hand, a number of refinery project managers have no technical approach to the issue of paints and some of them consider it as one of the last priorities. Unfortunately, sometimes the project manager tries to compensate for the delay in completing the project by reducing the surface preparation and paint application time, and orders for increasing the speed of the paint operations.