Sanding wooden floors as a part of the floor restoration process is an important step. First question which usually comes in mind is related to the type of equipment it should be carried out with.
The "mighty" belt sander is a good mate in most of the floor restoration works we may face. However, when dealing with hardwood floors in relatively good condition, it may slow us down. In fact, if the lack of experience exists as an issue in our confidence, it may even cost us more than just the time.
Sander Orbital
Finishing wooden floors with an orbital sander or a Trio-like sander (having in mind the popular Lagler Trio machine or similar) will achieve the better and quicker results on even floors with a relatively good state. Help yourself remove the previous sealant and continue working on achieving smooth surface.
If the floor involves planks or boards (especially pine floor boards) you might find it difficult to work with the rotary type of machines. The "mighty" belt comes on help again.
Start with the lower grid belts and go up the ladder to the finer ones. Once the perfect level is achieved you can either move to the rotary machine or continue with the finer grids and smaller friends of the belt - the Edger and Corner machines.
Don't forget the buffing step with a very fine grid or a buffing screen, after your first / second coat of sealing - the most important step in the fine finishing of the wooden floors.
Summary: Choosing the right equipment is based on your judgement for the level of the floors and their condition. Poorly fitted or floors with physical damage / repaired floors would be assisted by the belt sander and the rotary machine will help you finish quicker on wooden floors in relatively good condition / wearing.