P5 - Pump Cavitation - Physics, Prediction, Control, Troubleshooting

Short CourseThis short course gives insight into roto-dynamic pump cavitation and provides deeper understanding of particulars like cavitation inception, three-percent head drop, 40,000 hours life criterion, cavitation damage potential, NPSHR scaling laws, the effect of dissolved gas, and thermodynamic effect for hot water and hydrocarbons. Empirical correlations for predicting various types of NPSHR and the use of CFD will be discussed, and suction specific speed will be critically reviewed, along with criteria for NPSHA margin. Furthermore, the effect of fluid transients and viscosity will be addressed. Cavitation damage potential will be fully explained by the Cavitation Modes Map, which reflects fundamental insight gained since the 1940s; here in particular the striking departure in shape from the NPSH3 curve for part flows is highlighted, being a key reason of many cavitation pump problems. Attention is further devoted to Impeller Life Expectancy and Cavitation Control with modern designs tools. In conclusion, four field case studies will demonstrate the use of cavitation failure analysis and solution strategy