Filters on reduction and extraction plants are found at many mines. A 800 x 20 mm (31.5" x 0.8") disc is used on these filters. The disc has slots cut into it and rotates between the suction pump and the header valve. Alternately, it closes off and then releases the air from the suction pump.

Vescolene Ultrablack, an Ultra High Molecular Weight Polyethylene is used in this hard wearing, dirty application. Ultrablack is a superior material for heavy duty, wear resistant applications. It is about five times more wear resistant than ordinary high density polyethylene grades and gives superior wear and abrasion resistance to conventional ultra high molecular weight polyethylene's.