Axial flow pumps are machines that convert mechanical energy into kinetic energy by increasing the pressure of a liquid through centrifugal force. Liquids are virtually uncompressible so they themselves cannot be pressurized and reduced in volume. They can, however, be influenced by centrifugal force, the force that causes substances to move away from their center of rotation; they submit to the pressure of this force and are directed into, through and out of the pump.

Axial flow pumps consist of an impeller, a volute or casing and a motor and are made of aluminum, cast iron or stainless steel. Axial flow is one of three kinds of flow generated by centrifugal pumps along with radial and mixed flow. Axial flow pumps are commonly used for lifting and transporting water, a valuable application that finds use in commercial, industrial, general purpose and residential environments. Centrifugal pumps are used in wastewater and sewage treatment plants to handle trash and refuse. As water pumps, axial flow pumps can move water from its underground source to buildings for human use and are also used for drainage and to transfer shipping ballast. Axial flow pumps are heavy duty and, when made of high grade materials, can pump corrosives, adhesives and chemicals. For example, pumps move liquids from bulk storage, transport them to a mixer or processor then dispense them into individual containers.
Centrifugal pumps have a simple design. An impeller is mounted on a rotating shaft inside a volute, or casing, that expands in size in order to slow the liquid while increasing the pressure until it reaches the discharge opening. Axial flow pumps use the same principles except that the impeller lifts the liquid in a direction parallel to the pump shaft instead of pushing it in a perpendicular direction. The impeller is similar to a propeller on a boat. Axial flow pumps use the propeller to create a lifting action in addition to imparting the liquid with rotational kinetic energy. The blades or vanes on the propeller are angled to move through the liquid in such a way that their movement causes the liquid to move in an opposite direction; that is, to move up. Axial flow pumps are examples of vertical pumps that can be placed in well holes due to their upright shafts. If the pump is submerged in water or placed underground, the motor that drives the propeller will be kept in a sealed enclosure as most submersible pumps are, or mounted to the pipe from the outside. By changing the pitch or angle of the propeller, the flow rate and pressure will be adjusted accordingly. Because axial flow pumps have the smallest dimensions of the three kinds of centrifugal pumps, they are suited for low heads (output pressure measured in pounds per square inch) and higher discharges (measured in gallons per minute or hour).