The book "Control Valves" by Alejandro Orvieto Riga offers a comprehensive analysis of processes in the petrochemical industry, particularly regarding the application of control valves. It addresses specific cases, such as sulfur recovery plants and the Jose terminal station, and provides solutions for process regulation. The challenges encountered in gas desulfurization and pressure regulation are described in detail, including issues such as cavitation and high pressure differentials that can lead to noise and vibration problems. The book includes important concepts, equations, and methodologies that assist the reader in sizing and selecting control valves. The illustrative images and clear structure of the content make it a valuable reference for professionals in the petrochemical industry.