The new BTH range combines the various advantages of product group T. It is characterized by a separately driven, concentrically rotating ribbon screw with a maximized diameter and a long pitch. Through separate control of the conveying screw speed, the BTH pump can be used for almost any conveying media. The variable speed auger screw permits optimum filling of the conveying elements rotor and stator without causing excess capacity in the stuffing box. Even media that tend to forms bridges can be handled with ease due to the large screw diameter of the BTH pump. The BTH range is the technically optimum solution for shear sensitive conveying media.