Operating a reciprocating air compressor without an air filter will cause __________.

Correct Answer: Option C — excessive wear on valves and cylinder liners

Air filters prevent atmospheric dust and grit from entering the compressor. Without filtration, these abrasive particles enter the cylinders, mixing with lubricating oil to form a grinding paste. This causes rapid, excessive wear on precision components like valves, piston rings, and cylinder liners, significantly shortening the compressor's service life.