Tennessee Wastewater Operator Practice Exam

In a blower system, what is a primary drawback of using rigid couplings?

1. They require frequent replacements

2. They can transmit excessive vibration

3. They are expensive

4. They are difficult to install

The correct answer is: They can transmit excessive vibration

Rigid couplings are mechanical devices used to connect two shafts together in a blower system, ensuring that they rotate in unison. A primary drawback of using rigid couplings is their ability to transmit excessive vibration from the motor to the connected equipment. When the motor or blower experiences any form of misalignment or imbalance, a rigid coupling does not compensate for these discrepancies. Instead, it allows vibrations to pass directly through, which can lead to wear and tear on components, increased noise levels, and potential damage to the blower system itself. The other options mentioned do have their respective drawbacks but do not capture the primary concern associated with the use of rigid couplings in this context. Frequent replacements typically relate more to flexible couplings, while cost and installation difficulty vary based on the specific system design and application. Thus, the transmission of vibration poses the most significant risk factor and concern for operational stability in blower systems using rigid couplings.