Plant Operator Selection System Test Plant Operator Selection System Reading Comprehension 3 — Questions and Answers
Question 1: Read the following passage and answer the question. "During startup of a centrifugal compressor, the antisurge valve must remain fully open until the machine reaches minimum operating speed. Closing the valve prematurely can cause surge, which produces damaging pressure oscillations throughout the system." What is the consequence of closing the antisurge valve too early?
- The compressor reaches minimum speed faster
- Pressure oscillations that can damage the system (Correct answer)
- Increased efficiency during startup
- Reduced noise during the startup sequence
Correct answer: Pressure oscillations that can damage the system
The passage states premature valve closure can cause surge, which produces 'damaging pressure oscillations throughout the system.'
Question 2: Read the following memo excerpt and answer the question. "Effective Monday, all shift operators are required to complete the pre-shift checklist before signing off on equipment status. The checklist must be signed by both the departing and incoming operators. Unsigned checklists will be treated as incomplete and reported to the shift supervisor." What happens if a checklist is not signed?
- The shift supervisor must complete it instead
- It is destroyed and a new one must be filled out
- It is treated as incomplete and reported to the supervisor (Correct answer)
- The outgoing operator must remain on duty until it is signed
Correct answer: It is treated as incomplete and reported to the supervisor
The memo states unsigned checklists 'will be treated as incomplete and reported to the shift supervisor.'
Question 3: Read the following passage and answer the question. "Turbine oil must be sampled quarterly and analyzed for viscosity, water content, and particulate contamination. If any parameter falls outside the acceptable range specified in the manufacturer's manual, the oil must be replaced or remediated before the next scheduled sample." How often must turbine oil be sampled?
- Monthly
- Every two months
- Quarterly (Correct answer)
- Annually
Correct answer: Quarterly
The passage explicitly states turbine oil must be sampled 'quarterly,' meaning once every three months.
Question 4: Read the following passage and answer the question. "Flow meters can drift over time due to wear, coating buildup, or damage. A field verification check compares the meter reading against a reference measurement. If the two values differ by more than 2%, the meter must be recalibrated or replaced." A flow meter reads 100 GPM while the reference measurement shows 104 GPM. What action is required?
- No action; the difference is within acceptable limits
- Recalibrate or replace the meter (Correct answer)
- Increase the flow to match the meter reading
- Document the reading and check again next month
Correct answer: Recalibrate or replace the meter
A difference of 4 GPM on a 104 GPM reference is approximately 3.8%, which exceeds the 2% threshold, requiring recalibration or replacement.
Question 5: Read the following safety bulletin and answer the question. "Hydrogen sulfide (H₂S) is an extremely hazardous gas. It is heavier than air and tends to accumulate in low-lying areas such as pits, sumps, and trenches. Workers entering these confined spaces must use supplied-air respirators regardless of detector readings." Why does H₂S pose a particular hazard in pits and trenches?
- It rises to the top of confined spaces
- It is lighter than air and disperses slowly
- It is heavier than air and accumulates in low areas (Correct answer)
- It reacts with concrete surfaces to form toxic compounds
Correct answer: It is heavier than air and accumulates in low areas
The bulletin states H₂S is 'heavier than air and tends to accumulate in low-lying areas such as pits, sumps, and trenches.'
Question 6: Read the following procedure and answer the question. "To verify a pressure relief valve (PRV) is functional: (1) Ensure system pressure is at least 10% below the PRV set pressure. (2) Manually lift the PRV test lever briefly. (3) The valve should discharge and then reseat firmly when the lever is released. (4) If the valve fails to reseat, isolate the system and notify the supervisor immediately." What must an operator do if the PRV does not reseat after testing?
- Lift the test lever again to force reseating
- Continue normal operations and note in the log
- Isolate the system and notify the supervisor immediately (Correct answer)
- Increase system pressure to force the valve closed
Correct answer: Isolate the system and notify the supervisor immediately
Step 4 of the procedure states that failure to reseat requires the operator to isolate the system and notify the supervisor immediately.
Question 7: Read the following passage and answer the question. "Operators should not rely solely on instrumentation when assessing equipment condition. Regular walkarounds allow operators to detect abnormalities — unusual sounds, vibration, odors, or visible leaks — that instruments may not capture. These observations should always be logged." Which of the following best states the main idea of this passage?
- Instruments are unreliable and should be replaced with manual inspections
- Physical walkarounds complement instruments by detecting what sensors may miss (Correct answer)
- Logging observations is the most important task of an operator
- Unusual sounds are the most important indicator of equipment problems
Correct answer: Physical walkarounds complement instruments by detecting what sensors may miss
The passage argues that walkarounds 'complement' instrumentation by detecting abnormalities 'that instruments may not capture,' making physical inspection a supplement, not a replacement.
Plant Operator Selection System Test Plant Operator Selection System Reading Comprehension 3
Read the following passage and answer the question.
"During startup of a centrifugal compressor, the antisurge valve must remain fully open until the machine reaches minimum operating speed.
Closing the valve prematurely can cause surge, which produces damaging pressure oscillations throughout the system."
What is the consequence of closing the antisurge valve too early?