The air compressor shown in the illustration, when used aboard a vessel is typically operated as __________. Illustration GS-0119

Correct Answer: Option D — a constant capacity unit

Constant capacity units, often referred to as constant speed compressors, operate by cycling between load and unload modes based on discharge pressure. They maintain a consistent motor speed while the unloading mechanism regulates the actual air delivery, ensuring the system pressure remains within the required operating range for shipboard services.