Basic Wastewater Operator Practice Exam

What will occur if the bearings on horizontal centrifugal pumps are over lubricated?

1. May cause overheating and possible failure of the bearings

2. It is impossible to over lubricate the bearings on horizontal centrifugal pumps

3. Horizontal centrifugal pumps do not have bearings

4. The bearings on horizontal centrifugal pumps are sealed and do not require lubrication

The correct answer is: May cause overheating and possible failure of the bearings

Over-lubricating the bearings on horizontal centrifugal pumps can lead to a significant increase in operating temperature. When too much lubricant is added, it can create excessive friction and hydrodynamic issues within the bearing. This can prevent the bearing from functioning correctly, causing it to retain heat rather than dissipate it. Over time, this overheating can lead to a breakdown of the lubricant itself and result in bearing wear or even total failure. Proper lubrication is essential for the optimal performance and longevity of the pump; maintaining the appropriate level is vital to ensure efficient operation and avoid costly repairs associated with bearing failure. The other choices suggest misunderstandings about how lubrication works in this context. While it is indeed true that some pumps may have sealed bearings which require less maintenance, most horizontal centrifugal pumps do have bearings that need appropriate lubrication levels to function correctly.