A Sure-Seal™ actuated spout clamping system seals the bag discharge spout for dust-tight operation, while a Flo-Master™ bag massaging system and rotary valve provide reliable metering of materials during drum filling. A powered Flo-Lock™ discharge spout closure system quickly halts material flow for partial bag discharging. Drum filling system features a dust-tight actuated filling head, densification system, gain-in-weight scale system, and gravity roller conveyor. System is designed for Class II, Division II, Group G service.