Automatuc Compressor Drain Valve Kit

I have a 1/4 in. nylon hose on the drain line that sneaks out in the little gap at the bottom of the garage door.

 

Since my compressor is back in the far corner of the garage, and I haven't drilled a hole through the wall for the drain hose, I drain my condensate into a big clear plastic pretzel container. I just crack the ball valve open, and at pressure, get a steady stream of rust stained water. I keep the end of the hose near the bottom of the container. After a quart or more, it starts to sputter. I shut off the valve and empty the container. Then I come back and crack the valve open a little wider (with the end of the hose back in the container) to blow off the remaining moisture.
-Donny

 

How big of a tank do you have? I drain my 2 gallon pancake compressor after use, but that's a whole different animal than my 80 gallon!

 

So, just to continue this conversation, wouldn't a drastic change in pressure also create moisture?

My 80 gallon hardly ever kicks on unless I'm using it for an extended period, and I only seem to get a cup or less of rusty water weekly. I've seen moisture buildup in my empty compressor too, which leads me to believe it's inevitable.

Once this one rusts enough to have a pinhole, it's probably time to upgrade or rebuild the pump and motor anyways!

 

The air is hot from compression, and I'd guess the cooling of the air when you shut down would induce some additional condensation. The vapor pressure of water gets lower as the temperature goes down (cold -> dry). When the compressor is running, the higher pressure of the air lowers the saturation limit (dew point) and forces the water vapor in the air to condense. I would expect this to be a much larger effect than cooling.

 

yup, same way I do it.

 

Must be nice to live in such a dry location. I've drained my condensate 2-3 times a day when I'm sandblasting, with a quart or more each time. Temperature and humidity!
-Donny

 

Which state are you in? I drain mine about once a year or when the air coming out the hose gets wet, usually not a problem at least for air tools, sandblasting and painting I could see being a different story and needing a dryer in line.

 

The air coming out of the hose is always wet. Try aiming it at a cold surface and you'll see the condensate.

 

I have a ~30g Quincy roller. A few years ago, the drain was full, trickled out of drain. Took for ever.

Let the pressure off, opened tank caps, rinsed inside with a high pressure sprayer, recapped, and then repressured.

Used the air to further dry, now flowed good out of drain petcock.

I drain it when i think of it. Sounds like something to do this weekend. Might look at a ball valve drain config.

Great discussion.