UFL650: The UFL650 mechanical seals are specially developed for high temperature applications with wide range of sliding velocities. Its torque transmission exerts no strain on the bellows. This seal design requires no elastomer secondary seals. UFL850N: Mechanical seals in the UF850N series have a universal field of application. They are designed for extreme temperatures for high viscous medias. UFLWT800: Seal faces are positively driven to protect the bellows from torsional stress. Secondary seals are made of high temperature resistance flexible graphites.