I am probably saying a similar thing as Caso, but I was given a tip that proved to be absolutely solid.. The air compressor puts out very hot air. Hot air doesn't release its humidity until it cools. I used to have a water trap right out of the compressor and it was always dry. I was told to move that trap 25 feet away from the compressor and I was shocked to see it half full after a few hours of constant use.
So now, my pipes come out of the compressor, but the water trap is 25 feet away. I have a prefilter which is nothing more than an HF glass water trap, then a Devilbiss OC3 dessicant water trap with regulator. The prefilter catches a lot of the water but not nearly all, then the OC3 gets the rest. I have a totally waterless painting experience that way.
To prove the 25 ft thing, just run an air hose between the compressor and the water trap and you will see the significant difference.
