4. Driving elements: pumps

4.1 Classification

Pumps are classified into two main categories based on their operating principle and the way in which energy is transmitted to the fluid:

• positive-displacement pumps whose flow rate depends only on the speed of rotation, but is independent of the discharge pressure. Fluid transfer is achieved by displacing an elementary capacitance characteristic of the pump's moving parts. The way this capacity is generated leads to two categories of positive-displacement pumps: reciprocating positive-displacement pumps and rotary positive-displacement pumps;

• dynamic" pumps, which transmit a load to the fluid, depending on the flow rate. An impeller provides the fluid with kinetic energy, which is...