CWEA MECHANICAL TECHNOLOGIST
GRADE 5 EXAM QUESTIONS AND
VERIFIED ANSWERS
1. In vibration analysis, a spectrum showing a high peak at 2x the running speed in the radial
direction most likely indicates which condition?
A. Angular or parallel misalignment
B. Mass imbalance
C. Mechanical looseness
D. Bearing outer race defect
Answer: A
Conceptual Explanation: Misalignment typically produces high 2x RPM peaks in the radial
direction and high 1x peaks in the axial direction.
2. According to the Pump Affinity Laws, if the speed of a centrifugal pump is doubled, how
does the power requirement change?
A. It doubles
B. It increases by a factor of 4
C. It increases by a factor of 8
D. It remains the same
,Answer: C
Conceptual Explanation: Power is proportional to the cube of the speed ratio (2 cubed =
8).
3. What is the primary purpose of an API Plan 53B Piping Plan?
A. To provide atmospheric cooling for a single seal
B. To quench the seal with low-pressure steam
C. To flush the seal chamber with process fluid from the discharge
D. To maintain a pressurized barrier fluid using a bladder-type accumulator
Answer: D
Conceptual Explanation: Plan 53B uses a pressurized bladder accumulator to maintain
barrier fluid pressure in dual seal arrangements.
4. In Reliability Centered Maintenance (RCM), what is defined as a ‘Hidden Failure’?
A. A failure that is not apparent to the operating crew under normal circumstances
B. A failure that results in a catastrophic explosion
C. A failure occurring in a system that has no monitoring
D. Corrosion occurring inside a sealed pipe
Answer: A
, Conceptual Explanation: Hidden failures typically involve protective devices that are not
required to function until another failure occurs.
5. Which formula correctly represents the Net Positive Suction Head Available (NPSHa)?
A. Hatmos - Hvapor + Hvelocity
B. Hstatic + Hvelocity - Hfriction
C. Hatmos + Hstatic - Hfriction - Hvapor
D. Hdischarge - Hsuction
Answer: C
Conceptual Explanation: NPSHa is the atmospheric pressure plus static head, minus
friction losses and the vapor pressure of the liquid.
6. What does the ‘P-F Interval’ represent in predictive maintenance?
A. The time between equipment purchase and first failure
B. The time required to perform a preventative maintenance task
C. The time between a potential failure being detected and functional failure occurring
D. The frequency of scheduled inspections
Answer: C
Conceptual Explanation: The P-F interval is the window of time available to intervene
after a defect is detected but before the asset stops performing its function.
GRADE 5 EXAM QUESTIONS AND
VERIFIED ANSWERS
1. In vibration analysis, a spectrum showing a high peak at 2x the running speed in the radial
direction most likely indicates which condition?
A. Angular or parallel misalignment
B. Mass imbalance
C. Mechanical looseness
D. Bearing outer race defect
Answer: A
Conceptual Explanation: Misalignment typically produces high 2x RPM peaks in the radial
direction and high 1x peaks in the axial direction.
2. According to the Pump Affinity Laws, if the speed of a centrifugal pump is doubled, how
does the power requirement change?
A. It doubles
B. It increases by a factor of 4
C. It increases by a factor of 8
D. It remains the same
,Answer: C
Conceptual Explanation: Power is proportional to the cube of the speed ratio (2 cubed =
8).
3. What is the primary purpose of an API Plan 53B Piping Plan?
A. To provide atmospheric cooling for a single seal
B. To quench the seal with low-pressure steam
C. To flush the seal chamber with process fluid from the discharge
D. To maintain a pressurized barrier fluid using a bladder-type accumulator
Answer: D
Conceptual Explanation: Plan 53B uses a pressurized bladder accumulator to maintain
barrier fluid pressure in dual seal arrangements.
4. In Reliability Centered Maintenance (RCM), what is defined as a ‘Hidden Failure’?
A. A failure that is not apparent to the operating crew under normal circumstances
B. A failure that results in a catastrophic explosion
C. A failure occurring in a system that has no monitoring
D. Corrosion occurring inside a sealed pipe
Answer: A
, Conceptual Explanation: Hidden failures typically involve protective devices that are not
required to function until another failure occurs.
5. Which formula correctly represents the Net Positive Suction Head Available (NPSHa)?
A. Hatmos - Hvapor + Hvelocity
B. Hstatic + Hvelocity - Hfriction
C. Hatmos + Hstatic - Hfriction - Hvapor
D. Hdischarge - Hsuction
Answer: C
Conceptual Explanation: NPSHa is the atmospheric pressure plus static head, minus
friction losses and the vapor pressure of the liquid.
6. What does the ‘P-F Interval’ represent in predictive maintenance?
A. The time between equipment purchase and first failure
B. The time required to perform a preventative maintenance task
C. The time between a potential failure being detected and functional failure occurring
D. The frequency of scheduled inspections
Answer: C
Conceptual Explanation: The P-F interval is the window of time available to intervene
after a defect is detected but before the asset stops performing its function.
