Fourth Edition, May 2020 - This updated guideline is meant to specify the technical requirements of pumps, homogenizers and dampening devices including their hygienic application in order to ensure a safe processing and production of food under hygienic conditions. The requirements described in the guideline apply to all pumps intended for the use in safe food processing, including centrifugal pumps, piston pumps, lobe rotor pumps, peristaltic pumps, diaphragm pumps, progressive cavity pumps, screw pumps as well as to homogenizers and dampening devices.