Air compressor tank auto drain

[Darrell Bade]

Guess my Google search wasn't terrible, it brought up a lot of the electronic ones. I had not seen them before, I thought the float type was all there was. Float type makes more sense to me. The one link Bruce listed had one on that page.

[David Buchhauser]

I use a small valve like the ones used on evap cooler water lines, then just leave it cracked open a slight amount with a pan underneath. It is a very small leak, but when it gets humid any moisture in the bottom of the tank drains into the pan and evaporates. I'm not a big fan of the auto drains with timers. I like to keep it simple.

If you look closely between the legs of the belt sander you can see the drain pan (an old pie tin) next to the bottom of the compressor. My compressor came with a drain valve located at the bottom of the tank, but I removed the valve and installed a 90 degree fitting with a short length of pipe which protrudes out beyond the tank for easy access.

David

compressor.jpgdrain pan.jpgdrain pan 1.jpg

[Tom M King]

I did the same piping the drain out to where it can easily be accessed. That's the first thing I do with one. I changed the valve to a good quality ball valve though that's easy to operate.

[Steven O Smith]

I made one using a time delay relay (mechanical) I found at the scrap yard and a solenoid valve. The relay stays on for a second (or whatever I have it set to) whenever power is applied to the motor.

[Keith Outten]

Darrell,

You had a pin hole in your tank and it didn't explode...your very lucky.

Years ago a 20 gallon air compressor blew up and totally destroyed a one car garage here in the county where I live. The owner had just left his shop and went inside for lunch. It blew all four walls out and the roof dropped straight to the ground.

Based on that accident and a few more we did a comprehensive non-destructive testing program at NASA Langley that included every high pressure vessel from huge air compressor stations and massive bottle fields to very small portable compressors. We kept very busy for several years replacing and repairing what we found from our inspection program.

I have been seriously considering purchasing an Ultrasonic Testing instrument to test my shop compressors and possibly do some free inspection for people in my area just because the danger of an exploding tank is a very serious event.

For all of you who have installed an auto-drain feature on your shop compressors, you did good!

[Jerome Stanek]

Darrell,

You had a pin hole in your tank and it didn't explode...your very lucky.

Years ago a 20 gallon air compressor blew up and totally destroyed a one car garage here in the county where I live. The owner had just left his shop and went inside for lunch. It blew all four walls out and the roof dropped straight to the ground.

Based on that accident and a few more we did a comprehensive non-destructive testing program at NASA Langley that included every high pressure vessel from huge air compressor stations and massive bottle fields to very small portable compressors. We kept very busy for several years replacing and repairing what we found from our inspection program.

I have been seriously considering purchasing an Ultrasonic Testing instrument to test my shop compressors and possibly do some free inspection for people in my area just because the danger of an exploding tank is a very serious event.

For all of you who have installed an auto-drain feature on your shop compressors, you did good!

My last compressor got a pin hole leak in the bottom and didn't blow up. Also 2 of the compressors at work got pin hole leaks and they didn't blow up

[mike calabrese]

Pin hole leaks are a result of corrosion mot likely. Corrosion in a compressor tank is dangerous. Think of it this way, it is like seeing a mouse in your house. If you see one you can bet your neck there are more. Check out compressor failures on youtube they are extremely powerful and potentially deadly.
be careful........
https://www.youtube.com/results?sear...r+tank+failure
https://www.youtube.com/watch?v=W2LbTHfU5fQ
calabrese55

[Chris Parks]

A good way to minimise tank corrosion is to remove the drain valve and add a high pressure line in its place and then put the drain valve at the end of that line. set the compressor on a slight angle and the condensate should collect in the extended line instead of the tank.

[mreza Salav]

What would be a reasonable approach for someone (like me) that doesn't use the compressor frequently? Currently whenever I want to use the compressor, shut the valve and turn it on, once done for the day open the valve (at the bottom) to drain (both air and water) and leave the valve open until you want to use it next time.

[Jim Becker]

I don't use my compressor "a lot" either, Mreza, and while I turn off power to it when I'm not in the shop, I just let the auto-drain take care of blowing out any moisture. It does drain down the tank eventually, but I know it's dry.

[Bill Dufour]

I have an electric drain powered from the same switched power to the motor. It lets out a puff every time the motor starts. It puffs about every ten minutes of continuous run time. I really should add a push button switch to drain it at the end of use. It takes.a long time for a 60 gallon tank to build pressure. It holds pressure for more then one month before the gauge gets below the low pressure cut in pressure. I had to repalce the check valve into the tank wehn I bought the used tank.
Bill D

[Bruce Page]

I power off the compressor at the end of the day and usually cycle the ADV once or twice. I will cycle it the next morning when I power up the compressor again. As I said above, I live in a dry climate. If I lived in a wetter climate I would likely do things differently.

[David Dille]

This is a puzzler to me. I had a 20 gallon Cambell-Hasfield for nearly 30 years. Would drain it about once per year. Mostly just a very tiny bit of moisture. Sold it 6 years ago but I know the guy. So this almost 40 year old compressor is still working fine without being drained constantly. My current compressor is a 30 gal oil. The drain plug for it, is not on the absolute bottom so I can’t drain it completely. When I do pop the cock, all I get is a tiny, tiny bit of oily mist. When I was young, about a thousand years ago, I worked in a Cat shop. We had several huge compressors. One was a 12.5 hp, the other a 10 hp. Huge tanks. I asked the head mechanic about draining them and he just laughed and said sure, if you can get to the drain, go for it. Well, I couldn’t get to the drains.

I did seismic drilling up on the North Slope of the Brooks Range in the very early 80’s and one year, we used what they call mud guns out on the ice of the Beaufort Sea. Seven stage compressors with a 7500 psi charge. I could see those taking out a house but it’s hard to believe a tiny shop compressor, maybe 20 gal, 2 hp, could rupture a tank enough to take out garage walls, just not enough volume, but hey, what do I know.

Anyway, I just don’t think it’s a huge deal. Again, totally unsupported opinion. Just based on my own 50 years of experience but certainly, err on the side of caution. 😀

[Jimmy Harris]

What would be a reasonable approach for someone (like me) that doesn't use the compressor frequently? Currently whenever I want to use the compressor, shut the valve and turn it on, once done for the day open the valve (at the bottom) to drain (both air and water) and leave the valve open until you want to use it next time.

Keep doing what you're doing. That's why I've always done, and pretty much everyone I know who owns a compressor outside of a commercial setting. It works fine if you're not using the compressor often. It's how they are designed to operate.

I've had several jobs where compressors ran at least 8 hours a day, five days a week, and often more. They need those automatic release valves. They cycle literally tons of air a day. So they'll build up lots of water without them. They have a near constant drain on the tank. And when the automatic valves do go off, they leave enough water to pool up on the floor. That's enough to rust a tank. On my home compressor, there might be enough water that you can feel the spray is wet when you empty the tank. But it doesn't make a pool of water below it. It just doesn't cycle enough air under my normal use to be a concern.