As you know the Flow-Rail system is comprised of an aluminum rail, chain and a 50’’ front head piece where pallets are loaded / unloaded.
This front head piece is very strong. As a result, regardless of pallet weight the first upright can be up to 48″ W.
In the event pallets are very heavy (3000lb++) it is likely a 3rd rail may be necessary.
This would result in an additional front head piece to help support the load on the 48’’W front uprights.
Refer to the Flow Rail Weight Load Capacity Chart for reference.