NCCER Millwright Practice Exam

A common observation in a failed mechanical seal is indeed leakage or loss of pressure. Mechanical seals are designed to prevent fluid from escaping the system, and when they fail, they typically allow the fluid to leak out. This can lead to a significant loss of pressure within the system, which can affect overall operational efficiency and may lead to more serious issues within the machinery if left unaddressed.

In the context of the other options, an increase in operational speed is not typically associated with seal failure; in fact, higher speeds can exacerbate the conditions leading to seal failure. Improvement in efficiency is highly unlikely, as a failed seal typically results in inefficiencies due to lost product and potential contamination. A decrease in vibration levels would not be expected with a failed seal; in many cases, vibration levels may actually increase due to improperly aligned or damaged components resulting from fluid leaks and the resultant changes in system dynamics.