CWEA MECHANICAL TECHNOLOGIST
GRADE 2 EXAM QUESTIONS AND
VERIFIED ANSWERS
1. Which of the following is the most likely result of a centrifugal pump operating at a point
far to the right of its Best Efficiency Point (BEP)?
A. Increased risk of cavitation due to high NPSH requirement
B. Decreased radial thrust
C. Reduced motor amperage draw
D. Lowered suction pressure velocity
Answer: A
Conceptual Explanation: Operating far to the right of the BEP increases the flow rate,
which significantly increases the Net Positive Suction Head Required (NPSHr), making
cavitation more likely if NPSHa is insufficient.
2. When using a dial indicator to perform a rim-and-face alignment, what does ‘indicator sag’
refer to?
A. The compression of the indicator stem under its own weight
B. A defect in the dial face calibration
C. The bending of the indicator mounting hardware due to gravity
,D. The movement of the shaft inside the bearing clearance
Answer: C
Conceptual Explanation: Indicator sag occurs when the weight of the indicator and its
mounting bracketry causes the hardware to flex downward, leading to inaccurate readings
if not accounted for.
3. A pressure gauge at the discharge of a pump reads 85 psi. If the fluid being pumped has a
specific gravity of 1.2, what is the equivalent head in feet?
A. 163.63 feet
B. 196.35 feet
C. 235.62 feet
D. 102.00 feet
Answer: A
Conceptual Explanation: Head (ft) = (PSI * 2.31) / Specific Gravity. (85 * 2.31) / 1.2 =
163.625 feet.
4. Which type of mechanical seal arrangement is designed specifically to prevent any process
fluid from leaking into the atmosphere by using a pressurized barrier fluid?
A. Single internal seal
B. Double (Barrier) seal
C. Tandem (Buffer) seal
, D. Quench seal
Answer: B
Conceptual Explanation: A double mechanical seal uses a barrier fluid maintained at a
higher pressure than the process fluid, ensuring that any leakage is of the clean barrier
fluid into the process, not vice versa.
5. What is the primary purpose of a ‘lantern ring’ in a stuffing box using compression packing?
A. To provide a sacrificial wearing surface for the shaft
B. To compress the packing rings evenly
C. To prevent the packing from rotating with the shaft
D. To allow for the injection of lubrication or flush water
Answer: D
Conceptual Explanation: The lantern ring is a spacer that allows cooling or lubricating
fluid to be injected into the center of the packing set to reduce heat and friction.
6. In vibration analysis, which symptom is most characteristic of a misaligned coupling?
A. High 2X axial vibration
B. High 1X radial vibration
C. Random high-frequency noise
D. Sub-synchronous peaks at 0.5X
GRADE 2 EXAM QUESTIONS AND
VERIFIED ANSWERS
1. Which of the following is the most likely result of a centrifugal pump operating at a point
far to the right of its Best Efficiency Point (BEP)?
A. Increased risk of cavitation due to high NPSH requirement
B. Decreased radial thrust
C. Reduced motor amperage draw
D. Lowered suction pressure velocity
Answer: A
Conceptual Explanation: Operating far to the right of the BEP increases the flow rate,
which significantly increases the Net Positive Suction Head Required (NPSHr), making
cavitation more likely if NPSHa is insufficient.
2. When using a dial indicator to perform a rim-and-face alignment, what does ‘indicator sag’
refer to?
A. The compression of the indicator stem under its own weight
B. A defect in the dial face calibration
C. The bending of the indicator mounting hardware due to gravity
,D. The movement of the shaft inside the bearing clearance
Answer: C
Conceptual Explanation: Indicator sag occurs when the weight of the indicator and its
mounting bracketry causes the hardware to flex downward, leading to inaccurate readings
if not accounted for.
3. A pressure gauge at the discharge of a pump reads 85 psi. If the fluid being pumped has a
specific gravity of 1.2, what is the equivalent head in feet?
A. 163.63 feet
B. 196.35 feet
C. 235.62 feet
D. 102.00 feet
Answer: A
Conceptual Explanation: Head (ft) = (PSI * 2.31) / Specific Gravity. (85 * 2.31) / 1.2 =
163.625 feet.
4. Which type of mechanical seal arrangement is designed specifically to prevent any process
fluid from leaking into the atmosphere by using a pressurized barrier fluid?
A. Single internal seal
B. Double (Barrier) seal
C. Tandem (Buffer) seal
, D. Quench seal
Answer: B
Conceptual Explanation: A double mechanical seal uses a barrier fluid maintained at a
higher pressure than the process fluid, ensuring that any leakage is of the clean barrier
fluid into the process, not vice versa.
5. What is the primary purpose of a ‘lantern ring’ in a stuffing box using compression packing?
A. To provide a sacrificial wearing surface for the shaft
B. To compress the packing rings evenly
C. To prevent the packing from rotating with the shaft
D. To allow for the injection of lubrication or flush water
Answer: D
Conceptual Explanation: The lantern ring is a spacer that allows cooling or lubricating
fluid to be injected into the center of the packing set to reduce heat and friction.
6. In vibration analysis, which symptom is most characteristic of a misaligned coupling?
A. High 2X axial vibration
B. High 1X radial vibration
C. Random high-frequency noise
D. Sub-synchronous peaks at 0.5X
