The radial screw pump is a volume-type self-suction pump with 2-axle screws. The liquid (fluid) is enclosed in a chamber formed by two screws and casing, and pushed out in the direction of thrust by the turning screws. The pump is designed as an "in-cylinder transfer" system, so it gets less radial load, and can transfer the materials smoothly without pulsation, agitation or shearing.
Also, it is structured so that no turning parts contact with each other, so no metal powder, etc., is generated by wear or mixed into the material. It generates no friction heat, so it does not damage a liquid which is sensitive to temperature change.
Moreover, it is under no restriction on the inlet bore because of its characteristics theoretically. Accordingly, it can have a larger inlet bore if required by the liquid (material) transferred, allowing efficient and smooth input and transfer of high-viscosity or other materials which tend to cause problems in inputting them. For dried out or bridge-forming materials, the model with a screw conveyor(PAT.P) or paddle is available.

- Principle of operation of the screw pumps