QA is a very versatile type of light duty racking. It is also looked upon as a heavy duty shelving, but no matter what it is known as, the one feature it offers is very quick assembly.
It can utilize beams as a standard pallet rack, or, through the addition of shelf supports and galvanized panels, it is then transformed into a heavy duty shelving unit.
The first photo below would represent the top and bottom levels of a typical bay of QA. These two levels will be the main support of the frame work, and special panels will drop in to set in the special ledge which is formed at the back of the beam.
The second photo shows the additional levels. They use shelf supports which clip in to the frames on either side. Special panels are then placed onto the ledge of the shelf support brackets.