You don’t need an expensive water trap what you need to do is put a minimum 20 or 30 feet of hose between your compressor and your water trap...this distance will allow the water vapor to cool down enough for the water trap to do its job... I don’t use an oiler I just use “gun” oil in the tool at least once before use… I use a 25 year old commercial 240v 6hp compressor @ 140 pounds that is has been plugged in continuously for over 15 years…powering nail guns and mechanic’s tools, as well as my air brush….if you’re going to leave it plugged in all the time the trick to long life for your air compressor is to install a check valve in the discharge line and install a “head un-loader” that will take the head pressure off the reed valves…