» Cartridge construction» Pre-assembled» Static compression unit» Balanced Applications: Slurries, viscous media, paper and pulp. Cartridge seals, as the name suggest are preassembled, factory tested, balanced seals, 'Fit-it, Bolt-it' design makes these seals most easy for installation. Spring protected 'O' ring design allows the seal to work in viscous and abrasive media. Specially designed dynamic elastomers and seal faces make the seal fret-free.