Compressor automatic Drain

[GarageGuy89]

Would like to get one of these, that is the ones that are controlled via 120v switch.

Everything I see is around $100 for one of these and up. I don't mind spending that kind of money if that is what a quality one costs. I would expect them to cost a bit less though...

What are you guys using? And any recommendations?

 

[Rag Roc]

I manually drain mine right now, but we have the $100 automatic ones on the compressors here at work, and have worked great for 4+ years now. Ours plug directly into a 110v outlet and are programmable for how often, and how long they flush. The only downside (if you want to call it that) is they flush whether the compressor is on or not, and will empty the tank of air after a few days.
I do have one on my shopping list.

 

[redmondjp]

I just put a 120VAC solenoid valve on the bottom of my tank, with a momentary pushbutton mounted near the top. I hit the button whenever I am near the compressor to open or turn off the ball valve on its output.

The automatic ones drive me crazy, as they typically operate once every hour or so. Always scared the heck out of me (at one former place of employment) as I was never expecting to hear a loud blast of air at random times.

 

[BruceMc]

The automatic ones drive me crazy, as they typically operate once every hour or so. Always scared the heck out of me (at one former place of employment) as I was never expecting to hear a loud blast of air at random times.

The trick to those is to then put them on a timer so they only operate for a short time in the early A.M. hours.

I plugged this -

https://www.amazon.com/gp/product/B00UEU6XIE/?tag=atomicindus08-20

into one of these timers -

https://www.amazon.com/gp/product/B01LPSGBZS/?tag=atomicindus08-20

and set it so the drain is only energized early in the morning.

 

[Hawke]

I have one that automatically opens when tank pressure goes to 3 psi, so it works overnight.

 

[Jeff May]

I've been using the same thing BruceMc has shown on the post above.
I have two air compressors, each with seperate drain valves, they are both plugged into the same timer. It is set to allow each valve to activate about 2 seconds each time at various times throughout a 24 hour period.
They've been installed for at least 4 years and are working like they should.
I think I got mine off fleabay.

 

[dkmc]

Everything I see is around $100 for one of these and up.

You haven't checked EBAY have you.
They are on there from China for $22 and free shipping.
I have one and it works great.

 

[exranger06]

I plan on getting one of these and wiring it into the starter, so it only operates when the compressor is turned on. I'm going to have a remote toggle switch to turn the compressor on/off, and the drain will periodically drain only when the toggle switch is on.

 

[marinusdees]

I have two compressors feeding into one air system. One always on, maintains minimum 80 psi and one turned on when I need more air (and pressure) maintains minimum 125 psi. Both have a (cheap) timed drain bought on ebay, around $20 each. They are loud and startling when they drain every hour. I put a small engine muffler in the end of the drain line and put this into a plastic 5 gallon bucket with the lid on. Doesn't eliminate the noise, but makes it less obnoxious. The drains are always on so making noise when I am not in my detached shop. Maybe keeps thieves out??
I thought about putting the drain to the outside if the building. I think the noise might disturb the neighbors. Maybe not.

 

[matt_i]

I have a PLC control for other things and was thinking of adding an auto-drain via this strategy. About 20 minutes after the air compressor runs, purge the tank-drain for a few seconds. After that, no more draining until the next run-cycle. It needs some tuning and experimentation to arrive at the best parameters of course

It seems to me like the moisture is going to be present in the air that's compressed and then cools. But continuing to drain over and over is actually wasting air and, over time, bringing in more moisture as the cycles add up.

 

[Lelandwelds]

Simplest solution would be the air operated drain. Never had one. Always wanted one.

 

[marinusdees]

I have a PLC control for other things and was thinking of adding an auto-drain via this strategy. About 20 minutes after the air compressor runs, purge the tank-drain for a few seconds. After that, no more draining until the next run-cycle. It needs some tuning and experimentation to arrive at the best parameters of course

It seems to me like the moisture is going to be present in the air that's compressed and then cools. But continuing to drain over and over is actually wasting air and, over time, bringing in more moisture as the cycles add up.

You can set the purge time for automatic drains so that in that split second the air loss is minuscule and the compressor(s) don't cycle any more frequently than once in ten years, if that. I have never even spotted a drop of residual water in the 5 gallon bucket I use as mufflers. I can tell you that if I manually drain either compressor that has an auto drain, there is NOTHING there.

 

[marinusdees]

In my 30 years of practicing dentistry, I bought and tried numerous automatic drains, all of which operated on the pressure variation between high and low. Most bought at Grainger. They were expensive and prone to failure. I much prefer the auto electric drains. You can set the time between spurts and the length of the spurt. The longest time between drains is 45 minutes and should be much longer. This is why some of the earlier posters added an additional timer to control when the auto drain is functioning, so it doesn't drain so frequently. I have mine set to purge every 45 minutes (the maximum) for the minimum length of time. I think this is overkill, but as good as it gets, and, works enough for me. If the noise sets off your PTSD, plumb it out the wall and wake up the neighbors.

 

[BruceMc]

One thing I didn't mention - make sure that whatever you use, the default position for the valve is closed. That is, in the absence of power the valve remains shut (either if on a seperate timer or during a power outage). I think they're rare, but I did run across a couple of drain valves that relied on power to stay closed when I was shopping for mine.

 

[dkmc]

One things for sure, draining and wasting some air is way better than not draining at all because you forgot to do it manually.

 

[manwithtools]

Off delay relay (5- 10 sec) and a normally closed solenoid valve that opens whenever the compressor kicks on. The small delay in gaining pressure is not noticed and you are draining the tank every time the compressor starts.

 

[LifeLongWNYer]

This thread has me thinking. Who here knows how the "spitter" on trucks work? They spit out a bit of air and accumulated moisture each time the compressor unloads. Why wouldn't one of those work in a shop?



.

 

[dkmc]

Don't know how they work, but may be an interesting alternative.
I'm sure they are very reliable, because they have to be DOT approved.
Google shows they are not very expensive either....
I've played around with Bendix and WABCO truck air brake compressors years ago.
They are built like tanks. Also they have a nice constant run unloader or "governor" as they
call it. It's called a "D2 style governor". Could be adapted to unload other types of compressors....

EDIT: Here's a link to the Drain Valve manual
https://www.manualslib.com/manual/392619/Bendix-Dv-2-Auto-Reservoir-Drain-Valve.html#manual

 

[coljar]

I have one of the $100 jobs. I have a switch with a pilot light right above the work bench and the nice thing is, if you don't want to leave the switch on, you can still cycle the valve for a single blow off for the times you won't be running it much. It is piped so it blows off to the outside from the compressor which is located in the back room.

 

[Jvvmusme]

Off delay relay (5- 10 sec) and a normally closed solenoid valve that opens whenever the compressor kicks on. The small delay in gaining pressure is not noticed and you are draining the tank every time the compressor starts.

can you post a picture ?

 

[sberry]

I walk over and crack a valve once in a while, usually when I real a post about a problem with an automatic. Its just more junk added. I plumb a hose thru the wall, put a ball valve on, crack it once in a while depending on use.

All 3 vessels plumbed to a common hose thru the wall.

 

[Bretny]

I built a copper cooler between my compressor and 60gal tank. I get about 2oz of water out of the tank every few months. Most of it stays in the cooler thus i wont be rusting out a 60gal tank.
Im in the notheast.

 

[dkmc]

What's a copper cooper?
Post some pics, don't be a party pooper........sorry couldn't resist.

 

[930dreamer]

I'm guilty of only having a manual drain valve, but I did rebuild it so its within easy reach.

 

[brownbagg]

i put ball valves on mine and made a handle that goes three feet up the side of the tank,

 

[911mike]

I have an auto drain and it works fine. I put a 10 ft coil of copper tubing on the drain tank drain then the valve on the end of the tubing. This keeps any water in the copper tubing and not in the steel tank. Also I keep the blow off time at 2 seconds. Anything less I have had issues with dirt particles clogging the valve and it will not close 100%.

 

[Kaizen]

maybe a dumb question as i just have the factory screw i turn and tons of dirty muck comes out......with an auto drain or for those that have replaced the factory screw in with piping and a valve does the water get blown above the highest level of water in the tank? i like the piping idea into a larger container.

Are there any auto drains that you can control the amount it opens or use piping after the valve so its not so loud? i jump just when the compressor kicks on and i'm not using it.......i'd have a heart attack with 120 psi blasting out. plus im sure one of my friends would put an air horn on it eventually.

 

[sberry]

I had demo something and had that pile of copper water line laying around. I had to flare 1 piece to put it together. Drilled a hole thru the wall and shoved it thru with a rubber grommet on the outside. I really drain mine as per how much work it does and some humidity. If its hot and sticky drain it on occasion if I use it much. Its not an exact science and have seen them with gallons of water in them. I probably drain it 8 or 10 times a year. Having it plumbed out makes it all the easier vs trying to catch pee in a jug.