UPVC borewell casing is the modern alternative to mild steel in formations where corrosion is the primary long-term threat — coastal zones, high-chloride aquifers, and formations with elevated iron content that would attack MS casing from the inside out. Duke and Astral manufacture IS 12818 certified UPVC casing to exacting tolerances.
Plain Casing vs Ribbed Screens
- Plain Casing (CS): Used in non-water-bearing formations — provides structural support through rock and clay layers where water intake is not desired
- Ribbed Screen (RS): Used in water-bearing aquifer zones — precision-slotted to allow water entry while excluding sand particles larger than the slot width
Slot Size Selection
Slot width must be selected based on aquifer grain size analysis. For fine-grained alluvial aquifers common in the Sabarmati basin, 0.5–0.75mm slots are typically specified. For coarser gravel aquifers, 1.0–1.5mm slots provide greater flow without sand ingress.