Rotary Seals Standard Materials: 75 Duro NBR (Nitrile, Buna N) 80 Duro FKM (Fluorocarbon) Additional materials may be available. Contact VanSeal for details. Pressures to 500 psi High Pressure Rotary Seals Standard Materials: 75 Duro NBR (Nitrile, Buna N) 80 Duro FKM (Fluorocarbon) Additional materials may be available. Contact VanSeal for details. Pressures to 1,500 psi