Mechanical Systems & Equipment Flashcards
7 cards from real CPE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Mechanical Systems & Equipment flashcards as text
Which maintenance strategy uses real-time condition monitoring data to schedule repairs only when needed?
Answer: Predictive (condition-based) maintenance
Predictive maintenance uses sensor data (vibration, temperature, oil analysis) to detect deterioration and schedule intervention before failure occurs.
A plant engineer must select a pump for a high-viscosity fluid. Compared to water, operating with a viscous fluid will:
Answer: Decrease flow, head, and efficiency
Higher viscosity increases internal fluid friction losses, reducing pump flow, head, and efficiency compared to the water-based pump curve.
What is the purpose of dynamic balancing (two-plane balancing) vs. static balancing?
Answer: Dynamic balancing corrects couple imbalance in wide rotors; static balancing only corrects static imbalance
Two-plane dynamic balancing corrects both static and couple (dynamic) imbalance, which is essential for wide rotors where imbalance planes are axially separated.
In a screw conveyor design, increasing the screw pitch will primarily:
Answer: Increase conveying capacity for the same speed
A larger screw pitch moves more material per revolution, increasing volumetric conveying capacity at the same rotational speed.
An engineer notices a pump's performance curve has shifted left (reduced flow at given head). The MOST likely cause is:
Answer: Worn impeller reducing effective diameter and clearance
Impeller wear increases running clearances and reduces effective diameter, causing the pump curve to shift downward and to the left.
Which type of valve is BEST for throttling (flow control) service in a plant piping system?
Answer: Globe valve
Globe valves are designed for throttling because their plug-and-seat design provides fine, controllable flow regulation across a wide range of positions.
The term 'mechanical efficiency' of a pump refers to:
Answer: The ratio of hydraulic power output to shaft power input
Mechanical efficiency is the ratio of useful hydraulic power delivered to the fluid to the shaft brake power input, accounting for all mechanical and volumetric losses.