2nd Class Power Engineering (2B3) Practice Exam

The component that is specifically designed to remove moisture and oil from compressed air is the oil separator. Oil separators are critical in ensuring that the compressed air system operates efficiently and that the quality of the air is maintained for its intended use.

When air is compressed, it tends to pick up moisture from the environment due to temperature changes and pressure differences. Oils from the compressor can also contaminate the air. An oil separator uses various methods, such as centrifugal force, to extract oil droplets and coalesce them for removal, thus preventing oil contamination in the air system.

In relation to the other options, while an intercooler and an aftercooler might help manage temperature extremes and improve the efficiency of a compressed air system (by cooling the air), they do not specifically address the removal of oil and moisture. An expansion tank, on the other hand, is designed to handle reservoir capacity and pressure fluctuations but does not filter air or remove contaminants. Therefore, the oil separator is the essential component for maintaining the integrity of compressed air by eliminating unwanted moisture and oil.