Which type of pump has neither volute nor diffuser vanes?

An axial-flow pump is characterized by its design that allows fluid to flow parallel to the pump shaft, as opposed to the more commonly known centrifugal pumps, which utilize a volute or diffuser to convert kinetic energy into pressure. In an axial-flow pump, the impeller's blades force the fluid to move along the axis, meaning that there are no volute or diffuser vanes present in its construction. This design is particularly useful for applications requiring high flow rates and low pressure, such as in irrigation systems or flood control. The absence of these components in an axial-flow pump distinguishes it from other types of pumps, which typically use volute or diffuser mechanisms to achieve their intended fluid dynamic functions.