Non-return valves of plastic [parts of machines]; reversible flow filters [parts of machines]; filtering machines; filter presses for chemical processing; filtering machines, separators and centrifuges; filter housings being parts of machines; filters for machines; melt filters; filters being parts of machines or engines; cartridges for filtering machines; sieves [machines or parts of machines]; machines for processing plastics; machines for the plastics processing industry; screen changers; ...