Cavitation in piping occurs due to what phenomenon?

Cavitation in piping primarily occurs due to pressure drops that lead to the vaporization of the fluid. When fluid flows through a pipe and encounters a sharp bend or obstruction, the flow velocity increases, which in turn can cause a significant drop in pressure at that point. If the local pressure falls below the vapor pressure of the fluid, vapor bubbles begin to form. This bubble formation is what is referred to as cavitation.

When these bubbles collapse, they create shock waves that can cause physical damage to the pipe and other components in the system. Therefore, the phenomenon of cavitation is closely associated with the dynamics of high-velocity flow and the resulting pressure changes, making the correct choice one that describes these conditions. The other options do not directly relate to the primary cause of cavitation in the same way that pressure drop does.