2. THEORETICAL FOUNDATIONS

2.3 Calculation of operating point

2.3.3 Operating point of the equipment team

It is about finding the point of service of our team, the point where the level of the pump characteristic curve and the point the level of the team have the same value (as shown in figure 2 for practice).

Apart from the operating point of the pump, we must also take into account the NORMA DIN, the specific regulations where it is indicated what kind of centrifugal pump we must choose to achieve the best performance..

In the graph is shown the model of the volumetric flow for the pump's performance, the power as function of flow, height as function of the flow and the diameter of the roller.

If you look carefully, we see the initials NPSH (Net Positive Suction Head). This parameter helps us to avoid the cavitations of the pump. Cavitations occurs when the liquid starts to boil inside the pump and cause pump wear. It can form an explosive atmosphere.

In order that this phenomenon does not happen, we must work with a higher value of the NPSH recommended by the manufacturer.