The Split Frame Unloader allows discharging of bulk bags and rigid totes from mezzanines and other low headroom areas. The unit allows the upper frame to be forklifted onto the plant floor, loaded with a bulk bag, and then forklifted back onto the subframe within several inches of the ceiling. For discharging from bulk bags, the subframe is equipped with a power-cincher flow control valve that cinches the bag spout concentrically on a horizontal axis for easy tie-offs, and vertically in a tight zigzag pattern to prevent leakage of fine powders. It also allows full-open discharge from bag spouts of all popular diameters and is USDA accepted.