Air dryer
The trick is to run your air from the compressor through 50' of galvanized pipe that zigzags up the wall to the ceiling and then drops straight down to a ball valve. Midway on that final drop of pipe, add a pipe that goes up about a foot to feed your water trap and subsequent dry air supply.
The length of pipe cools the warm moisture laden compressed air causing the water to condense out of it. By the time it gets to your water trap, most of the water is already gone.
I built this set-up in my garage after finding diagrams on the web. I've never had one drop of water in my water trap. It all drains out the galvanized pipe drop traps.