High Sealing Performance Alumina Ceramic Seal for Shut-off Valve. Superior Wear Resistance: Over 276 times more wear-resistant than stainless steel for extended durability. Exceptional Hardness: Hardness reaches up to 1700 MPa, nearly as hard as diamonds. Chemical Stability: Resistant to most strong acids and alkalis for harsh environments. Eco-friendly Safety: Material fully meets FDA and LFGB safety standards. Precise Dimensions: Consistent dimensions ensured via fine grinding and strict quality control. Customization Support: Custom-made options available for materials, dimensions, and designs. Low Surface Roughness: Fine polishing better than Ra0.3, diamond polishing better than Ra0.1. Temperature Resistance: Unaffected by temperature extremes, sand, rust, and severe water conditions.