Which of the following pump types is classified as non-dynamic?

The correct choice is reciprocating pumps, which are classified as non-dynamic pump types. Non-dynamic pumps operate by using a mechanism to create a change in volume, which moves the fluid through the pump. In the case of reciprocating pumps, they use a piston within a cylinder to draw fluid in and then push it out, creating a positive displacement. This means that the flow rate is determined by the speed and stroke length of the piston rather than relying on kinetic energy from fluid movement.

In contrast, the other types of pumps listed—centrifugal, mixed flow, and axial flow—are all dynamic pumps. These pump types utilize rotational energy and the principles of fluid dynamics to increase the velocity of the fluid, with centrifugal pumps, for instance, moving fluid by means of a rotating impeller. Mixed flow and axial flow pumps also rely on similar principles, harnessing dynamic forces to move fluid continuously without the displacement characteristic inherent in reciprocating pumps.

Understanding the differences between these categories is crucial for selecting the appropriate pump for a specific application in millwright work.