For the last 2 years I have been opening up the ball valve at the bottom of my 20 gallon IR air compressor tank to drain off any accumulated water. I had been contemplating an auto drain valve that opens on every cycle, but no water ever came out. Then I realized the valve isn't at he bottom of the rounded tank, its slightly higher than the lowest point, so I titled the tank and a bunch of water came out.
The compressor is kept in conditioned space so, even though I am in south Texas, the AC is running almost year round, and heated a few weeks in the winter,
So what do people do to maintain/properly drain these tanks? Tilt it all the time? What is the value of an auto drain if there is still water in the bottom of the tank below the valve height.