CPT Preventive Maintenance Procedures 3 — Questions and Answers
Question 1: What does an elevated bearing temperature during a PM inspection most likely indicate?
- Normal operation at full load
- Insufficient lubrication or bearing wear (Correct answer)
- Correct alignment
- Proper seal condition
Correct answer: Insufficient lubrication or bearing wear
Elevated bearing temperature typically signals insufficient lubrication, overloading, misalignment, or internal bearing wear.
Question 2: Which PM task helps prevent cavitation damage in a centrifugal pump?
- Checking and adjusting suction pressure and NPSH conditions (Correct answer)
- Increasing discharge valve throttling
- Reducing motor voltage
- Applying grease to the impeller
Correct answer: Checking and adjusting suction pressure and NPSH conditions
Verifying adequate suction pressure and Net Positive Suction Head (NPSH) prevents cavitation, which erodes impellers and internal pump components.
Question 3: How does predictive maintenance differ from preventive maintenance?
- Predictive maintenance is performed on a fixed calendar schedule
- Predictive maintenance uses condition monitoring data to determine when maintenance is needed (Correct answer)
- Preventive maintenance uses vibration analysis exclusively
- Predictive maintenance only applies to electrical equipment
Correct answer: Predictive maintenance uses condition monitoring data to determine when maintenance is needed
Predictive maintenance relies on condition monitoring (vibration, temperature, oil analysis) to schedule work based on actual equipment condition rather than fixed intervals.
Question 4: What is the function of a strainer or filter in a PM inspection on a process system?
- To measure fluid velocity
- To remove particulates that could damage downstream equipment (Correct answer)
- To increase system pressure
- To regulate fluid temperature
Correct answer: To remove particulates that could damage downstream equipment
Strainers and filters trap particulates to protect downstream pumps, valves, and instruments from erosion and plugging.
Question 5: A PM procedure requires replacing a V-belt drive. What inspection step is essential AFTER installation?
- Painting the belt for identification
- Checking belt tension and sheave alignment (Correct answer)
- Welding the sheave to the shaft
- Applying lubricant directly to the belt surface
Correct answer: Checking belt tension and sheave alignment
After V-belt installation, correct tension and sheave alignment must be verified to prevent slipping, excessive wear, or bearing overload.
Question 6: When mixing lubricants during a PM task, what is the MAIN concern?
- Color mismatch in the lubrication report
- Incompatibility between different lubricant base stocks or additive packages (Correct answer)
- Increased viscosity always improves performance
- Synthetic oils cannot be used in any process equipment
Correct answer: Incompatibility between different lubricant base stocks or additive packages
Mixing incompatible lubricants can cause additive precipitation, viscosity changes, or sludge formation that degrades lubrication performance.
Question 7: Which PM activity helps ensure accurate flow measurement in a process plant?
- Draining the flow transmitter impulse lines of any accumulated liquid or gas (Correct answer)
- Replacing flow meters annually regardless of condition
- Increasing orifice plate bore size
- Bypassing the transmitter during calibration checks
Correct answer: Draining the flow transmitter impulse lines of any accumulated liquid or gas
Draining or venting impulse lines removes condensate or trapped gas that can cause erroneous differential pressure readings on flow transmitters.
CPT Preventive Maintenance Procedures 3
What does an elevated bearing temperature during a PM inspection most likely indicate?