Abstract: An automatic bag filling machine employs a reduced pressure or a vacuum within a bag enclosing shroud to draw powdered material at a high velocity into either valved bags or vapor barrier bags to fill the bags with a relatively compacted powder. The shroud has powered movable liner assembly for adjustably enclosing bags of various size. A filling spout and a vapor barrier spout carrier by the shroud each have an expandable boot member to seal the mouth of the bag on the spout to preclude seepage of powdered material from the bag interior during filling. A system is provided for automatic detection of powder escaping from a broken bag. The shroud is supported on a weighing scale which measures the bags and stops flow when filled to a predetermined amount. Alternatively, the weighing scale may support the bag being filled inside the shroud. A filter tank connected to the machine reduces the discharge of powdered material into the surrounding atmosphere, and allows waste material to be reclaimed.