This is a conveying machine designed for handling high-viscosity and high-concentration fluids. It is a high-efficiency, positive-displacement pump characterized by low rotational speed and strong self-priming capabilities. It utilizes a pair of helical lobe rotors driven in counter-rotation by synchronized gears on parallel shafts; this action continuously creates sealed cavities between the rotors and the pump casing. The medium filling these cavities is steadily pushed by the rotating rotors from the inlet to the outlet.

The Guotai unloading and tank-scavenging pump is a twin-rotor positive displacement pump featuring German-derived technology. Capable of handling gas-liquid mixtures, it can completely empty the medium from road tankers and fully clear the upstream piping. Because it supports gas-liquid mixed transport and allows for prolonged dry running, it offers faster unloading speeds than other pump types under identical operating parameters; consequently, it is widely used by Sinopec and PetroChina.

Crude oil and fuel oil are characterized by high viscosity and significant content of non-hydrocarbon compounds, resins, and asphaltenes. Guotai rotor pumps—featuring low rotational speeds, virtually pulsation-free operation, and gentle fluid handling—effectively address these challenges, ensuring stable, vibration-free performance under conditions of high pressure and high viscosity.