Features & Benefits: The concentric disc offers bi-directional service and allows high Cv values with its symmetric shape Primary seal is formed by the disc hub and stem top， the seat contact exceeds the pressure rating of the valve Secondary stem seal is suitable for high pressure and is self-adjusting Disc hub edge are rounded and hand polished to provide full concentric sealing without seat obstruction to flow， combined with maximum seat life Replacement seat isolates the stem and body parts from the stream and also serves as the flange gasket Moulded-in O-ring provides positive