Which type of valve is used to release small pockets of air in a pipeline?

The air release valve is specifically designed to allow small pockets of air that can accumulate in a pipeline to escape. This is crucial in maintaining the efficiency and integrity of water distribution systems, as trapped air can create pressure fluctuations, reduce water flow, and even cause pipeline failures if not managed properly. These valves automatically open to release air when the pressure inside the pipeline drops below the atmospheric pressure, ensuring that the system remains fully pressurized with water.

Other types of valves serve different purposes: check valves prevent backflow, gate valves are used to start or stop the flow of water entirely, and pressure relief valves are designed to release excess pressure in a system to prevent damage. Each of these has a distinct function that does not include managing air within the pipeline, highlighting the specialized role of the air release valve in maintaining operational efficiency.