Petroleum refineries are costly and complex facilities made up of different systems, equipment, vessels, and machinery. These systems and components include many valves, instrumentation, filters, bolts, screws, fittings, and other parts. To ensure a refinery's continued efficient operation and minimize costly and time-consuming malfunctions, a refinery dedicates large portions of its operating budget to maintaining and repairing systems and equipment. Personnel who understand the types and importance of maintenance and repairs are crucial to a refinery's operations. The Maintenance Requirements in Petroleum Refining training course discusses the role and types of refinery maintenance. It also explores the purpose of a refinery turnaround. This online course is part of the Petroleum Refining training series.