A system protects an outlet of a pneumatic conveyor. The outlet has a horizontal section. The system comprises a deflector for protecting the horizontal section, and sets of stanchions therefor respectively attached to clamp assemblies mounted on the horizontal section. The deflector comprises angled walls, a plurality of crossbeams interconnecting the angled walls for reinforcing the deflector, and an end flange. Each stanchion has a foot. Each clamp assembly comprises two equal halves, fasteners joining together the equal halves, and a flange for each equal half perpendicular thereto. The system further comprises fasteners each attaching one foot to one flange, respectively.