Alternate vanes on the valve of a rotary feeder for feeding particulate material effect clearances with the surrounding feeder housing surface to effect desired, controlled flow of the particulate material. The clearances between the alternate vanes and the housing may comprise a variety of forms such as notches disposed in the alternate vane distal edges. Also, the radial length of the alternate vanes may be shortened to effect the desired clearances. Such clearances also greatly increase the permissible feeding rates.