Air from a compressor always carries water, oil and dust. Compressed air at 80 degrees Celsius drops litres of condensate a day once it cools in the tank. That water destroys plasma nozzles, spots paintwork and bursts tools in winter, so air treatment is part of the installation, not an add-on.
A refrigerant dryer brings the dew point down to about 3 degrees Celsius and is enough for most workshops. Size it with a margin, because catalogue capacity is quoted at 25 degrees at the inlet, while a hall in summer runs at 35 degrees and real capacity drops by roughly a quarter.
Build the filter train in stages. A 5 micrometre pre-filter stops water and coarse dust, a 0.01 micrometre coalescing filter catches oil mist, a carbon filter removes odour when spraying. For plasma a filter with a separator plus a dryer is enough, for painting take the full set.
An extra tank improves the whole installation: it evens out pressure under peak demand, cools the air and drops out some water before the dryer. For distribution use pipe with an inside diameter of at least 20 mm on runs over 20 metres, because a narrow pipe alone can cost you 1 bar.