Insulation Application Alumina Ceramic Sealing Ring / Washer. Super Long Service Life: Offers a super long service cycle compared to metal mechanical seals, reducing maintenance time. Extreme Chemical Stability: Resists hot strong acid and alkali, free of rust forever, suitable for severe environments. Superior Wear Resistance: Wear resistance is over 276 times that of stainless steel. Diamond Polished Surface: Features a diamond polished surface with roughness as low as Ra0.1 for perfect sealing. Customization Support: Supports custom-made demands based on different materials, dimensions, and designs. FDA & LFGB Compliant: Materials are eco-friendly, safe, and meet FDA and LFGB standards completely. Precision Manufacturing: Ensures consistent dimensions every batch via fine grinding and CNC machining.