Devices that allow material flow, but prevent the back flow of air or gas are important components in many conveying systems. They are commonly used wherever dry solids need to be moved between areas of differing air pressure. Process Barron manufactures rotary airlock feeders and double dump valves which can handle a variety of materials and presures. Rotary Airlock Feeders and Double Dump Valves are typically constructed of carbon or stainless steel with hard surfacing of the internal components as required for the particular application.