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

Correct Answer: Option A — seal failure usually requires the immediate removal of the pump from service

Mechanical seals provide a superior, near-leak-free seal compared to conventional packing. However, they are precision-engineered components. Unlike packing, which can often be adjusted or added to while in service, a mechanical seal failure is typically catastrophic, requiring immediate pump shutdown and disassembly to replace the damaged seal faces or bellows.