Air valves are used for the release of air pockets in water lines. When air is allowed to accumulate in pressurized pipelines, efficiency is sacrificed and serious damage can occur. An air valve is designed to allow the automatic discharge of large amounts of air from the water main, while it is being filled, and also to allow air to enter the water main, when the water line is being emptied. It will also allow the air to escape the water main when it is in operation and under pressure. If air valves are not installed, uncontrolled air releases may occur, causing pressure surges in the system and increased hazards from cavitation. This 2-hour course will describe the basic theory of air valves; explain their operation, and list ways and tools to specify, to locate, and to size them for maximum flow efficiency and surge protection.

Learning Objectives

• How does air get into the system?
• What problems are caused by trapped air?
• What are some types of air release valves?
• Where should these valves be located?
• How do you size the air valves?
• What are the available options/devices for air release?