Rotary Airlock Valves are a type of rotary feeder and are often referred to simply as a Rotary Airlock or Rotary Valve. They provide feeding and metering functionality of a standard rotary feeder but their primary duty is to maintain pressure and provide an optimal airlock seal between different product conveying transitions, such as gravity to pneumatic conveying lines. An optimal airlock condition is essential to prevent air pressure loss in high pressure and high temperature conveying systems.