MMC Predictive & Preventive Maintenance 4

Question 1

Which parameter measured during laser shaft alignment indicates angular misalignment?

Accepted Answer

Difference in slope between driver and driven shaft centerlines

Answer

Angular misalignment is indicated by a difference in the slope (angle) of the two shaft centerlines, measured as a gap difference across the coupling face.

Question 2

In predictive maintenance, 'severity criteria' for vibration measurements are used to:

Accepted Answer

Determine safe operating limits and trigger maintenance actions at defined thresholds

Answer

Severity criteria (such as ISO 10816 levels) establish alert and danger thresholds so maintenance actions are triggered at the right time based on measured vibration levels.

Question 3

When balancing a rotating component, 'residual unbalance' refers to:

Accepted Answer

The unbalance remaining after a balancing correction has been applied

Answer

Residual unbalance is the amount of unbalance that persists in the rotor after the balancing process is complete, which should meet the tolerance for the machine's speed and mass.

Question 4

A plant switches from time-based bearing replacement to vibration-based on-condition replacement. The most significant expected benefit is:

Accepted Answer

Extension of bearing service life and reduction of unnecessary replacements

Answer

On-condition replacement allows bearings to run until degradation is detected, avoiding premature replacement of serviceable bearings while still preventing run-to-failure.

Question 5

Infrared thermography on a refractory-lined furnace wall identifies a cold spot. This most likely indicates:

Accepted Answer

Refractory degradation or loss causing increased heat loss through the shell

Answer

A cold spot on the outer shell typically indicates that the refractory lining has thinned or deteriorated, allowing more heat to escape and raising shell temperature (or revealing a gap).

(MMC) Maintenance Management Certification Practice Test

(MMC) Maintenance Management Certification Practice Test

MMC Predictive & Preventive Maintenance 4