Hoppers for vacuum cleaners, vacuum loaders, dust collectors, wet industrial vacuums, dry industrial vacuums, and pneumatic conveyors; portable hoppers, hoppers with self-dumping discharge gates, hoppers with bottom dump gate valves, hoppers with hand wheel slide gates, portable end dump hoppers, and hoppers moveable by forklift trucks; all of the preceding hoppers for use with vacuum cleaners, vacuum loaders, dust collectors, wet industrial vacuums, dry industrial vacuums, and pneumatic conv...