Coast Guard Exams
Question 311General Subjects - QMED70% to pass

One disadvantage of using a mechanical shaft seal instead of mechanical packing is that _______________.

AI Explanation
The correct answer is A) seal failure usually requires the immediate removal of the pump from service. Mechanical shaft seals are designed to provide a tight seal between the rotating shaft and the stationary pump housing. Unlike mechanical packing, which can be tightened to maintain the seal, a mechanical shaft seal does not have this adjustment capability. If the seal fails, it typically requires the immediate removal of the pump from service to replace the seal, as continuing to operate the pump with a failed seal could lead to further damage to the pump. The other answer choices are incorrect because: B) mechanical seals do not require periodic disassembly and adjustment like packing, C) mechanical seals can be designed for high-pressure applications, and D) mechanical seals can also be used in high-temperature applications.