The cutter heads on quarrying and mining machines are fed with water, not only for cooling purposes but also for settling the dust and extinguishing any sparks produced by the cutting tools. Mechanical Seals perform the dual function of a rotary joint and a seal for the cutter and roller heads. Sealing systems used on these equipment are exposed to abrasive and chemically aggressive media. In some applications, high temperature and pressure make conditions even more challenging. Despite the harsh operating environment, users expect high reliability to avoid costly downtime.