What is the definition of a pneumatic valve? A pneumatic valve is a type of valve operated by compressed air. It is typically used in industrial and commercial settings to control the flow of liquids and gases. Pneumatic valves come in a variety of shapes and sizes, depending on their specific purpose. Generally, pneumatic valves are used to regulate air pressure, shut off a system, or direct the flow of a liquid or gas. They are also commonly used in applications such as controlling the flow of water, controlling the pressure of steam, and controlling the flow of air in a pneumatic system. Pneumatic valves can be operated manually or automatically, depending on the needs of the application. They are also available in a variety of materials, including plastic, metal, and rubber. Pneumatic valves offer numerous advantages, such as the ability to quickly respond to changes in pressure and the ability to control the flow of a system with precision.