Texas Commission on Environmental Quality (TCEQ). Class C Water License Exam

What is the consequence of starting a water lubricated vertical turbine pump with dry bearings?

1. The pump will operate at a higher efficiency

2. The bearings will be damaged

3. The water will not circulate

4. The pump will increase its flow rate

The correct answer is: The bearings will be damaged

When a water-lubricated vertical turbine pump is started with dry bearings, the lack of lubrication can lead to significant wear and damage to the bearings. Water serves as the primary lubricant to ensure smooth operation and reduce friction between moving parts. Without the necessary lubrication, the bearings experience excessive friction and heat, which can cause them to overheat, wear out, or even seize completely. This situation may result in permanent damage to the bearings, necessitating repairs or replacement, and ultimately can lead to significant downtime and costs for the system. The other options do not accurately reflect the consequences of starting the pump under such conditions. For instance, the pump will not operate more efficiently without lubrication; rather, efficiency can drastically decline as a result of bearing damage. Additionally, flow rate and water circulation are not necessarily impacted directly by dry bearings in the initial sense but may become relevant as the condition leads to failure and subsequently affects pump performance.