Our chief engineer?s career spans 47 years in the pump industry, holder of many patents relating to Sewage, Grinder-Pumps, and level controls.  Worked on Grinder Pumps during early 1960?s, the beginning of the low pressure Sewer Grinder market, at that time there were only 2 major companies manufacturing grinder pumps during this time period. One company utilized progressive cavity design; the second company utilized conventional centrifugal designs.