MDE 11 End of Unit Quiz

Correct Answer:
C) The filter uses centrifugal force to separate contaminants from the oil.

Explanation: A centrifugal lubricating oil filter operates by spinning the oil at high speeds, which generates centrifugal force. This force pushes heavier contaminants, such as dirt, metal particles, and sludge, to the outer edges of the filter, effectively separating them from the cleaner oil. The clean oil can then be recirculated back into the engine, while the contaminants remain trapped in the filter.

Correct Answer: B) Inadequate maintenance of the separator

Explanation: Poor maintenance can affect the separator’s ability to properly separate contaminants, leading to oil carryover and subsequent oil loss.

Correct Answer: A) By preventing oil leakage through seal and joint failures

Explanation: Proper sealing and joint integrity prevent oil from leaking out of the separator, thus minimizing oil losses.

Correct Answer: A) Different types of contaminants require a different discharge frequency

Explanation: Different contaminants may have different effects on the purifier's efficiency and capacity, influencing how often discharges are needed. For example, heavier solids might require more frequent discharges than lighter contaminants.

Correct Answer: A) A larger capacity purifier will have a lower discharge frequency

Explanation: A purifier with a larger capacity can handle more oil before needing to discharge contaminants, thus reducing the frequency of discharges.

Correct Answer: B) Regularly replacing the oil filters
Explanation: Regular replacement of oil filters helps in removing contaminants from the oil, thus preventing its deterioration.

These questions cover various aspects of maintaining the lubricating oil in optimum condition in a large medium-speed diesel engine.

Correct Answer: B) Ensuring proper engine warm-up before operation

Explanation: Properly warming up the engine ensures that it reaches operating temperature, reducing the risk of condensation and water contamination in the oil.

Correct Answer:
D) The filter causes small droplets of water or other liquids to merge into larger droplets, which are then separated from the oil.

Explanation: A coalescer lubricating oil filter works by using materials that cause small droplets of water or other liquids to coalesce, or merge, into larger droplets. These larger droplets are easier to separate from the oil, allowing them to be removed efficiently, thus purifying the oil from water or other liquid contaminants.

Correct Answer: B) It is capable of removing both solid and water contaminants simultaneously.

Explanation:
A coalescer filter is designed to remove water from fuel, but many coalescer systems are also equipped with pre-filters that can remove solid contaminants as well. This dual-functionality makes them particularly useful in ensuring the cleanliness and quality of the fuel before it is used in the engine.

• Correct Answer: B) It causes the oil to lose its ability to lubricate effectively

  Explanation: Water contamination dilutes the oil and disrupts its lubricating properties, leading to inadequate protection for engine components.

Correct Answer: B) To match the oil viscosity with the separator’s operational requirements

Explanation: Using the correct type of oil with appropriate viscosity ensures that the separator operates efficiently and minimizes oil losses.

Correct Answer: B) Viscometer test
Explanation: A viscometer test is used to measure the oil's viscosity, which is crucial for ensuring proper lubrication and engine performance.

These questions cover various aspects of assessing the condition of lubricating oil in a large medium-speed diesel engine on board a vessel.