The double mechanical seal of the MDH production line share the same technical advantages with the single MBC5 model. The structure of this sealing allows for a wide variety friction pairs usage and is repair-convenient. For mechanical ingredients containing liquids the friction pair is of tungsten carbide (WC) or silicon carbide (SiC). Used with mechanical ingredients containing and non-containing neutral and aggressive liquids transportation pumps. Widely used for sealing of vertical shafts of small and medium sized stirring devices.