IS 14428:1997 is the Indian Standard (BIS) for guidelines for painting structures in an aggressive chemical environment. This standard provides guidelines for selecting and applying protective paint systems on steel and concrete structures exposed to aggressive chemical environments, such as those found in industrial plants. It covers the classification of corrosive environments, detailed surface preparation methods, and recommendations for suitable multi-coat paint systems to ensure long-term durability.
Guidelines for painting structures in an aggressive chemical environment
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Standard for blast cleaning | Sa 2 1/2 as per Swedish Standard SIS 055900 | Sa 2½ ('Very thorough blast-cleaning') as per ISO 8501-1 | ISO 12944-4:2017 |
| Environmental category (e.g., coastal industrial) | Highly corrosive chemical fumes | C5 (Very High) or CX (Extreme) | ISO 12944-2:2017 |
| Typical DFT for an epoxy system in a severe environment | 175-200 µm (System No. 5 for acidic/alkaline fumes) | 240-320 µm (For a typical C5 'High' durability system) | ISO 12944-5:2019 |
| Primer containing chromate | Permitted and recommended (e.g., 'Zinc chromate primer' in Table 1) | Generally not recommended or prohibited due to health and environmental regulations; replaced by zinc phosphate or other inhibitors. | ISO 12944-5:2019 |
| Holiday detection guidance | Mentions using a holiday detector at a 'suitable voltage' without specific values. | Provides specific voltage calculation formulas based on coating thickness (e.g., V = M√T). | NACE SP0188-2022 |
| Concept of coating system durability | Implied by the system choice, but not explicitly defined as a selectable range. | Defined in time ranges: Low (L) 2-7 yrs, Medium (M) 7-15 yrs, High (H) 15-25 yrs, Very High (VH) >25 yrs. | ISO 12944-1:2017 |