This application includes companies engaged in metal working, manufacturing rolling metal production, cold forming mills, structural mills, and finishing equipment. Mill rolls are frequently reworked and polished with a roll grinder. Centerless grinders are typically inline feed units which do not require centering chucks. Typically, the grinding process is cooled and lubricated with a water-soluble coolant. The water-soluble coolant requires continuous filtration to maintain a very low contaminant level. Most often, the grinding filter of choice is typically a gravity filter or vacuum filter. Complete system packages including tanks, pumps, heat exchanger and controls can be proposed.