Mechanical sifting installations, namely, sieving machines, mechanical sifters, sifting machines, vibration sifting machines, drum sieve machines, screening machines, vibrating screen machines, classifiers for sorting or mechanical screening of materials by size, shape, and density, filter separators, namely, apparatus for separation, cleaning and purification of liquids and gases through filters for use in or as parts of machines and for removing particulate matter from gases, particularly d...