Rotary airlock valve dimensions are important when selecting a new valve or replacing an existing rotary feeder. A correct size check helps avoid installation mismatch, capacity loss and unnecessary modification work on site.  Key dimensions to confirm   Inlet and outlet flange size.  Overall height from inlet face to outlet face.  Body width, drive side clearance and motor position.  Shaft position and coupling or chain drive layout.  Rotor diameter, rotor length and pocket volume when available.  Flange drilling pattern and connection standard.   Dimensions for replacement projects  When replacing an old rotary valve, the most important data is not only the model name. Photos, flange drawings, center distance, overall height, drive direction and available space around the valve should be checked together.  Size chart limitations  A size chart is useful for preliminary selection, but the final model should also consider bulk density, capacity, material flowability, pressure condition, temperature and sealing requirements. Two valves with similar dimensions may not perform the same in different powder handling systems.  What to send for a quick check   Photos of the existing valve and nameplate if available.  Inlet and outlet flange dimensions.  Required capacity and material bulk density.  Operating temperature and pressure difference.  Whether the valve is used under silo discharge, dust collection or pneumatic conveying.   Related FUWEI pages  Use the  rotary valve sizing guide  for capacity and dimensional selection data. If the valve is worn, compare this with  rotary airlock valve troubleshooting  and  repair or replacement support .  Selection note  FUWEI can help review replacement dimensions after material data and installation photos are supplied. Do not change a published URL or flange standard without confirming the existing installation requirement.