A rotary plate feeder valve for use in pressurized pneumatic conveying systems. The valve comprises a rotary plate that is fed from a central inlet and discharges through a central outlet located immediately below the inlet. Located over the outlet discharge and within the valve body is a feed-rate control cone. Material transfer is controlled by rotary speed and feed-rate cone position. Several embodiments of the valve are disclosed including a nulllive-bottomnull embodiment designed to reduce or eliminate bridging in silos. Due to high clearances within the valve, the valve may be used with abrasive materials, delicate materials and foodstuffs.