Ink Pump Products Ink pumps for Flexo and Gravure applications have been Graymills business for over 50 years. Graymills has continually worked with Flexographic and Gravure press builders, converters and ink makers to develop centrifugal ink pumps, as well as peristaltic and diaphragm ink pumps, ink filters and ink circulating/conditioning systems. Graymills recognizes that needs vary from narrow-web flexo to large gravure presses, and has designed ink pump and ink delivery systems to meet this wide range of applications. In addition to ink pumps and ink filters, Graymills provides viscosity controls, ink tanks, hoses and fittings.