Filters are used in numerous processes and catch solids in a stream of fluids or gases. In the environment of fluid handling with pumps, a filter is generally used for separating undesired media in the fluid or for protecting valves, pipe systems, pumps and other components of the installation. Here it is used in valves, e.g. as a basket filter. Strainers or plug-in sieves are suitable for installation between standard flanges and available in different mesh sizes that are used according to the respective application. In general, a differentiation is made in the separation of solids and fluids between coarse filtration (separation of solids with a diameter of 0.5 to 5 millimeter), fine filtration (0.05 to 0.8 millimeter) and microfiltration (0.001 to 0.03 millimeter). Various materials are used as filter medium:
  • Rigid media made of fibers (often metal, but also plastic or ceramic) or granules
  • Flexible media such as webs, paper or fabric
  • Vibrating screens consist of a granular material through which the fluid handled passes