Cavitation occurs when the static pressure in a flowing liquid drops to or below the vapour pressure of the liquid, for example at constrictions or at high flow velocities. This forms vapour bubbles. When the pressure rises again, the bubbles collapse abruptly. If this happens close to a wall, the resulting micro-jet erodes material from the surface. In foundries, this mainly affects cooling water pumps and pipework.
References
- KSB SE & Co. KGaA: Centrifugal Pump Lexicon, article “Cavitation”. Accessed 27 August 2026.