The inlet hopper of the BTM chopper pump is rectangular, and axially-spaced rotary and stationary tungsten-carbide knives are used to chop, crush and feed products into the pumping elements. Rotating knives, symmetrically arranged on the feed screw, in conjunction with stationary knives fixed to the compression housing, chop and crush the fed product, allowing the macerated products to be transported without jamming or clogging the pump or discharge pipes. seepex, Inc., 511 Speedway Dr., Enon, OH 45323. Tel. (937) 864-7150; fax (937) 864-7157;