Corrective Maintenance Procedures Flashcards

During corrective maintenance on a mechanical seal, the technician finds fretting corrosion on the shaft sleeve under the old seal. The BEST corrective action is to:

Answer: Replace or re-sleeve the shaft to restore the required surface finish and diameter

Fretting corrosion creates surface irregularities that prevent the new seal from sealing properly; the shaft sleeve must be restored to OEM specifications.

What is the purpose of a 'bump test' during corrective electrical motor maintenance?

Answer: To verify correct shaft rotation direction before coupling to driven equipment

A bump test momentarily energizes the motor uncoupled to verify that shaft rotation matches the required direction before reconnecting the drive train.

Corrective maintenance on a reciprocating compressor reveals scored cylinder walls. Which measurement determines if honing or re-boring is required?

Answer: Cylinder bore diameter deviation from OEM specification, measured with an inside micrometer or bore gauge

Bore diameter measurements compared to OEM tolerance limits determine whether the cylinder can be honed within spec or must be rebored to the next oversize.

A corrective maintenance job requires welding on a vessel that previously contained flammable material. Before welding begins, the technician MUST:

Answer: Purge and test the vessel atmosphere to confirm it is below the Lower Explosive Limit (LEL)

Any residual flammable vapors can ignite during welding; the atmosphere must be tested and confirmed below LEL before any hot work is permitted.

After corrective maintenance on a chain drive, which parameter directly determines the correct chain tension adjustment?

Answer: Manufacturer-specified sag measurement for the chain span length

Correct chain sag (typically 2–4% of chain span) per the OEM specification prevents both premature chain and sprocket wear from over- or under-tensioning.

During corrective maintenance documentation, a technician should record 'as-found' conditions BEFORE making any repairs because:

Answer: As-found data provides the baseline for root cause analysis and prevents recurrence

As-found measurements and observations capture the failure state needed to identify root causes and implement changes that prevent the same failure from recurring.

A technician is completing corrective maintenance on a 480V motor control center bucket. Before closing the compartment door and re-energizing, the FINAL verification step should be:

Answer: Confirm all tools are removed, connections are torqued to spec, and the compartment is clear of foreign material

Foreign material intrusion (tools, hardware, wire scraps) inside energized switchgear is a leading cause of arc flash events and equipment damage.