Certified Maintenance and Reliability Technician (CMRT) Practice Test 2025 - Free CMRT Practice Questions and Study Guide

Cavitation in a pump occurs when there is insufficient net positive suction head (NPSH). NPSH is the difference between the pressure of the fluid at the pump inlet and the vapor pressure of the liquid. When NPSH is low, the pressure can drop below the vapor pressure of the fluid, causing vapor bubbles to form. These bubbles can collapse violently as they enter higher-pressure areas within the pump, leading to damage and inefficiency.

The correct understanding of cavitation highlights the importance of maintaining adequate pressure conditions at the pump's suction side. Insufficient NPSH could result from several factors, such as high elevation of the pump relative to the fluid source, blockages, or a poorly designed suction line. Therefore, maintaining a sufficient level of NPSH is critical to prevent cavitation and protect the pump's operational integrity.

In contrast, the other options do not directly lead to cavitation. Overfilling typically does not influence suction pressure directly related to cavitation. Operating at low temperatures can affect fluid viscosity and the dynamics of the fluid, but doesn’t necessarily result in cavitation without additional factors affecting pressure. High viscosity can create pumping challenges, but it does not cause cavitation in itself; rather, it might make