What is the primary cause of cavitation in a plumbing system?

Cavitation in a plumbing system primarily occurs due to high velocities around sharp bends. When fluid moves rapidly through a constriction or around a sharp turn, the pressure within the fluid can drop significantly. This drop in pressure can lead to the formation of vapor bubbles when the pressure falls below the liquid's vapor pressure.

As these vapor bubbles travel with the fluid and reach areas of higher pressure, they collapse or implode, which can cause significant damage to the piping and fittings due to the shock waves generated. This phenomenon is particularly prevalent in systems where the design causes high fluid velocities, making the understanding of the system's fluid dynamics critical for preventing cavitation.

This understanding highlights why high velocities at sharp bends are indeed the primary cause of cavitation, as opposed to other factors like slow-moving fluids or insufficient pressure, which do not create the conditions necessary for cavitation to occur.