Utah Water Distribution Practice Test 2025 – Comprehensive Exam Prep

If a pump sounds like it is pumping rocks, cavitation is the most probable cause. Cavitation occurs when the pressure in a pump falls below the vapor pressure of the liquid being pumped, leading to the formation of vapor bubbles. These bubbles form due to the rapid pressure changes within the pump. When the pressure returns to normal, these vapor bubbles collapse violently, creating a sound that can resemble the noise of rocks being pumped through the system.

This phenomenon not only generates noticeable noise but can also cause significant damage to the pump impeller and other internal components over time, leading to reduced efficiency and potential failure of the pump. Understanding and identifying cavitation is crucial for maintaining the performance and longevity of pumping systems.

The other options, while relevant in different contexts, do not typically result in the specific noise associated with cavitation. Air locks might cause the pump to operate inefficiently but wouldn't create a sound like rocks being pumped. A blockage in pipes would lead to reduced flow and pressure, possibly causing the pump to vibrate or labor, but the noise would differ from that of cavitation. An imbalanced impeller might generate vibrations and irregular sounds, but they would not mimic the sounds associated with cavitation.