Pumps are designed for conveying liquids and stuffs with wide range of viscosity, clean and polluted liquids, as well as abrasive stuffs with content of gases and/or fibrous and solid non-abrasive particles. They are used to advantage in foodstuff industry, as well as in pharmaceutical and chemical industries, etc. These pumps are applicable and efficient to pumping beverages, juices, syrups, beer, dairy products. Metallic components of their hydraulic part coming into contact with a pumped stuff are made of stainless steel.