External seal designed for the most critical applications on rotating equipment where the process fluids are highly corrosive and the metallic parts of the seal would normally be exposed to these harsh chemicals. The EFC seal is produced with the most modern materials and selected for its resistance to chemical attack. Following laboratory tests and multiple field trials on very demanding applications, the EFC seal has been meticulously designed to offer the best solution for sealing acidic products. This seal with Fluibi rotary ring version has the possibility to withstand the dry-running operation.