An axial-flow pump, or AFP, is a common type of pump that essentially consists of a impeller in a pipe operating in a casing. The pressure in the casing is developed by the flow of liquid over the blades of the impeller. The fluid is pushed in a direction parallel to the shaft of the impeller in course of their flow through the pump, do not change their radial locations. It allows the fluid to enter the impeller axially and discharge the fluid nearly axially. The propeller of an AFP is driven by a motor.
The impeller operates by a sealed motor in the pipe or by electric motor or petrol/diesel engines mounted to the pipe from the outside or by a right-angle drive shaft that pierces the pipe. Fluid particles, in course of their flow through the pump, do not change their radial locations since the change in radius at the entry (called ‘suction’) and the exit (called ‘discharge’) of the pump is very small. Hence the name “axial” pump. In an axial flow pump, blades have an airfoil section over which the fluid flows and pressure is developed.