I bought an air compressor at a garage sale. No tank, it rotted out. I ask a friend of mine to look in the scrap yard at the truck shop and get a couple of tanks discarded from a truck (about a foot in diameter and two feet long). Then I noticed he left the water drain valve on one of the tanks. The light went on and I have put the drain valve on my main tank and don't have to crawl under the tank (spiders and all) to open a drain valve. These have a cable attached and are spring closing so you pull the cable to empty the tank and when you let it go the valve automatically closes. you can ask a truck driver about them (all of us know and used one) and maybe they will have an extra to give to you or got to a truck parts store and ask for one. They can't be that expesive and it will be so easy to drain your tank (we have to every day on a truck) you will do it as you walk by. Oh by the way the trucks operate at 150 PSI so they will handle regular pressure.