The students explain the fundamentals of refrigeration, heating, ventilation, and air-conditioning. They also describe the operation of common components found in mechanical systems including valve actuators, air compressors, heat exchangers, diesel engines, strainers and filters. Bearings and the lubrication principles that maintain them in good working condition are described by the student. Students describe the basic principles of process measurement and control—actions that are crucial to plant operation—and the operation of power plant water treatment systems and equipment.