MBA 6.0/MBA 8.0 are designed for extreme ranges of temperature and for high-viscosity media. There is no dynamic O-ring and therefore a bellows seal will never hang-up. Used for a universal field of application, such as refinery, petrochemical, chemical, pharmaceutical, pulp&paper and food processing industry.welded metal bellow seal balanced no dynamic elastomer O'rings non-clogging even face load self cleaning  for hign viscosity temperature applications.