Hanna Rubber Carbon Compression Packings are manufactured from premium grade, low friction, high strength, proprietary graphite fiber to protect shafts from scoring. It also acts as a blocking agent to prevent wicking. Hanna Rubber Carbon Packings are ideally suited for use in severe service valves and rotary shaft applications handling strong acids and alkali solutions except fuming nitric acid, oleum and fluorine. They are used to seal steam, water, oil, solvents, alkalis, and acids and are often used as end rings for packing sets utilizing softer packings that might tend to extrude. This product group also handles high temperatures, extremely high shaft speeds, most strong chemicals, and reduces shaft wear.