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
In a shell-and-tube heat exchanger, baffles are installed to:
Answer: Direct shell-side flow across tubes and increase turbulence
Baffles force the shell-side fluid to flow perpendicular to the tubes, increasing turbulence and heat transfer coefficient while also supporting the tube bundle.
A plant engineer observes that a reciprocating compressor is running hot. Which cause should be investigated FIRST?
Answer: Fouled or leaking valves reducing volumetric efficiency
Leaking or fouled compressor valves cause gas recirculation and recompression, which generates excessive heat and reduces capacity.
The purpose of a pressure-compensated variable displacement pump in a hydraulic system is to:
Answer: Maintain constant pressure by varying flow output
A pressure-compensated pump automatically reduces displacement to maintain a set pressure, delivering only the flow needed to sustain that pressure.
Which lubrication regime is characterized by full separation of mating surfaces by a fluid film?
Answer: Hydrodynamic (full-film) lubrication
Hydrodynamic lubrication occurs when a pressurized oil film completely separates the surfaces, preventing metal-to-metal contact.
A plant uses a chain drive instead of a belt drive for a conveyor. What is the main advantage?
Answer: No slippage and positive mechanical drive
Chain drives engage sprocket teeth positively with no slippage, maintaining an exact speed ratio and enabling higher torque transmission.
When performing a vibration analysis, what does the overall vibration level in velocity (in/s RMS) primarily indicate?
Answer: The general severity of mechanical condition
Overall velocity RMS gives a single number representing total vibration energy, which is compared to ISO standards to assess machine health severity.
In a steam trap, the function is to:
Answer: Discharge condensate and air while retaining steam
Steam traps automatically discharge condensate (and non-condensable gases) from steam lines while preventing live steam from escaping.