In plumbing systems, what is usually a sign of cavitation?

A sign of cavitation in plumbing systems is usually excessive noise. Cavitation occurs when there is a rapid change in pressure in a liquid, leading to the formation of vapor bubbles in areas of low pressure. When these bubbles collapse or implode, they can produce loud noise, resembling a rattling or knocking sound. This excessive noise acts as an indicator that cavitation is occurring, which can be detrimental to the plumbing system, as it may lead to physical damage to components such as valves and pumps due to the shockwaves generated by the imploding bubbles.

While vibration of pipes, pressure drop, and water hammer can also be issues in plumbing systems, they are not the primary indicators of cavitation. Vibration can result from various factors unrelated to cavitation, like imbalance in rotating equipment or loose fittings. A pressure drop may occur for several reasons, such as obstruction or system demand changes, and while water hammer might involve transient pressure changes, it does not typically involve the vapor bubble dynamics characteristic of cavitation. Therefore, the noise produced is a more direct and clear sign of cavitation occurring in a plumbing system.