Grainger carries the Isolation Pads. They sell Campbell Hausfeld Compressors under their "Speedaire" Logo. I am certain there is a good explanation as to why to drain back into the Compressor, but I used 3/4" galvanized pipe unning at about waist level with drops every 5' or so. Then I put my air outlets above that downpipe and downstream.
As always, your mileage may vary-