Historically, most selective pallet rack systems have been designed with even spacing between loads and upright frames. As shown in Figure 1, 92-inch beams would be used with 4" spacing throughout, with standard 40-inch wide loads.
Figure1.
However, according to the National Fire Protection Association, there must be a six inch horizontal "flue space" between loads in a rack structure. This means that a 92-inch beam length may still be used, however the loads need to be located as shown in Figure 2, below:
Figure 2.
This variation in pallet location is the reason that you need to specify the location of pallet support bars when the beams are to be punched for this purpose. Examples include slots in step beams for snap-in supports, and holes in channel beams for bolt-in supports. Your installer will also need to be aware of this detail when installing pallet support bars that are attached to the beams using tek-screws.
Verifying the fire code used by the local building department will help you to be certain that your projects are fabricated and installed correctly.