OIT Maintenance and Troubleshooting 2 — Questions and Answers
Question 1: A pump is running but producing no flow. Which condition should you check FIRST?
- Discharge valve is closed (Correct answer)
- Motor is overheating
- Impeller is worn
- Bearing is failing
Correct answer: Discharge valve is closed
A closed discharge valve is the simplest and most common cause of no flow from a running pump.
Question 2: When performing a lockout/tagout procedure, what is the correct order of steps?
- Notify, isolate, lock, verify zero energy (Correct answer)
- Lock, notify, isolate, verify zero energy
- Isolate, verify, notify, lock
- Verify, isolate, lock, notify
Correct answer: Notify, isolate, lock, verify zero energy
LOTO requires notifying affected workers first, then isolating energy sources, applying locks, and verifying zero energy state.
Question 3: An operator notices excessive vibration in a centrifugal pump. Which cause is MOST likely?
- Impeller imbalance or cavitation (Correct answer)
- Low discharge pressure
- High suction head
- Excessive flow rate
Correct answer: Impeller imbalance or cavitation
Impeller imbalance and cavitation are the leading causes of abnormal pump vibration.
Question 4: What does a rising amperage reading on a motor suggest during normal operation?
- Increasing mechanical load (Correct answer)
- Decreasing voltage supply
- Motor is underloaded
- Cooling fan has failed
Correct answer: Increasing mechanical load
Rising amperage indicates the motor is working harder, typically due to increased mechanical resistance or load.
Question 5: Which type of bearing failure is characterized by a high-pitched squealing noise?
- Lubrication starvation (Correct answer)
- Overloading
- Misalignment
- Corrosion pitting
Correct answer: Lubrication starvation
Lubrication starvation causes metal-on-metal contact, producing a high-pitched squeal from the bearing.
Question 6: A pressure gauge downstream of a filter reads significantly lower than upstream. What does this indicate?
- The filter is clogged (Correct answer)
- The pump is oversized
- There is a leak downstream
- The filter is bypassing
Correct answer: The filter is clogged
A large pressure differential across a filter indicates accumulated debris is restricting flow.
Question 7: What is the primary purpose of a mechanical seal in a pump?
- Prevent fluid from leaking along the shaft (Correct answer)
- Reduce impeller friction
- Control discharge pressure
- Protect the motor windings
Correct answer: Prevent fluid from leaking along the shaft
Mechanical seals create a dynamic barrier between the rotating shaft and the pump casing to prevent process fluid leakage.
OIT Maintenance and Troubleshooting 2
A pump is running but producing no flow.
Which condition should you check FIRST?