CLS Case Analysis & Practical Application 2

Question 1

A conveyor drive gearbox operating in a food processing plant shows elevated iron particles in oil analysis. The plant requires H1-rated lubricants. Which corrective action is most appropriate?

Accepted Answer

Switch to a higher-viscosity H1-rated gear oil and monitor wear trend

Answer

Selecting a higher-viscosity H1-rated gear oil addresses the wear trend while maintaining food-safety compliance, and monitoring confirms whether the change is effective.

Question 2

An electric motor bearing running at 3600 RPM is being re-greased. The technician notices the grease fitting is packed solid with hardened grease. What is the best first step?

Accepted Answer

Clean and clear the fitting before introducing fresh grease

Answer

A blocked fitting must be cleared first so new grease actually reaches the bearing; forcing grease through a blockage can over-pressurize seals.

Question 3

Oil analysis on a hydraulic system reveals a particle count of ISO 23/21/17. The system specification calls for ISO 16/14/11 cleanliness. What action should be taken?

Accepted Answer

Flush the system and pass fluid through a kidney-loop filtration unit until target cleanliness is reached

Answer

Offline (kidney-loop) filtration is the most effective method to rapidly reduce particle counts to the target ISO cleanliness code.

Question 4

A plant engineer notices that two similar compressors have very different oil consumption rates. Compressor A uses twice the oil of Compressor B despite identical operating hours. What is the most likely root cause to investigate first?

Accepted Answer

Compressor A has worn piston rings or valve seals causing oil carry-over

Answer

Worn piston rings or valve seals allow oil to pass into the gas stream, dramatically increasing oil consumption in reciprocating compressors.

Question 5

During a lubrication audit, a technician finds that multiple lube routes mix NLGI 2 lithium-complex grease and NLGI 2 polyurea grease in the same bearing housings. What is the primary concern?

Accepted Answer

Incompatible thickener systems can cause grease softening and loss of lubrication

Answer

Lithium-complex and polyurea thickeners are often incompatible, and mixing them can cause the grease structure to collapse, leading to lubrication failure.

(CLS) Certified Lubrication Specialist Practice Test

(CLS) Certified Lubrication Specialist Practice Test

CLS Case Analysis & Practical Application 2