What are about the effect of temperature on NPSHR?
The cold water is a much “tougher” with regard to cavitation as compared to warm water. The explanation goes back to the fundamentals of thermodynamics of cavitation. The vaporization (boiling) of liquid in the process of cavitation is a thermal process, and depends on fluid properties, such as pressure, temperature, latent heat of vaporization and specific heat. To make vapor form, the latent heat of vaporization must be derived from the liquid flowing through the pump. This flow of heat can only be possible when the liquid temperature is above the saturation temperature at the main pressure in the low-pressure zone where cavitation is about to begin. In other words, the pressure in the cavitation region must fall below the saturation pressure corresponding to the liquid temperature. As we know, pump head begins to drop when cavitation begins – as bubbles block the passages more and more. Keep in mind that the term “pump head” ultimately means “energy per unit of mass flowing through
