The conveyance of water typically involves the transport of dissolved air, air bubbles, or air pockets that naturally occur or are introduced during the operation of the system. Air management in pressurized systems is complex due to various intervening factors, making comprehensive solutions challenging to achieve. Solutions include taking advantage of the dissolution of air in water, utilizing flow drag to carry air, employing protective equipment like air valves, and implementing monitoring strategies and operational controls. The wide range of potential situations involving air, along with their dependence on system characteristics and operational procedures—which can vary considerably during the system's lifetime—highlights the complexity of air management in pressurized systems. The interactions between air and water—either beneficial or detrimental—during unsteady, quasi-steady, and steady flows, including air admission, expulsion, forward and backward air movement, stagnation, and dissolution and release, remain critical areas of scientific and practical interest. This work aims to systematize the inspection and assessment of pressurized systems to identify air sources and management solutions, ultimately providing a framework for enhancing system efficiency, reliability, and safety. Moreover, this work provides practical examples from engineering practice and from experimental and numerical studies that highlight relevant issues related to air in pressurized water systems.