Draining your compressor

[thedoc46]

So, i know why you 'should' drain your compressor, to get the water out of it. and if you don't it could start to rust the compressor's innards.

But what about those of us that have large 30gal compressors ?

Is there any other option? Seems such as waste of energy, to drain out 30gallons of compressed air every time you go to use it.

I've just upgraded from an 8gal to a 29gal... It now takes 6mins to fill, pulling 13amps in the process.

Can i not, just open the drain valve for a few secs to get the moisture out, and leave it some pressure in it? Or does every last bit of air HAVE to come every night. I may only need to fire it up once a week, if that !

Or is there a special drain valve that just somehow gets the water out, and keeps the dry air in ? Surely gravity sees the water reach the bottom of the tank, and opening (along with the pressure expelling) takes most of the water out, within the first sec or two of opening.

Do they say drain every day just to be over cautious?

 

[Strouty]

Just drain the moisture.

 

[lakeroadster]

I just drain the moisture once a day, when I am using my compressor. Save the air for another day.

A simple street elbow, piece of pipe and a ball valve does the trick.

I built a puke tank for mine using a Folgers can and some kitty litter to capture the rusty water.....

A flap cut in the lid, and a shop rag between the lid and can, allows the pressure to escape / vent.

easy peazy.

 

[ryolse]

I put my little guy on it's own rotary wall timer with an automatic drain, the drain kicks on for 3 seconds (which can be adjusted) everytime I turn on the timer which both the compressor and valve are on. Then every 20 minutes that the timer is still on it bleeds off the air for a additional 3 seconds. The idea behind the timer is so that the compressor doesn't turn on unless I'm actually using it, it prevents the drain valve from draining the tank when I'm not using it and I've also added a Normally Closed "main line" valve to prevent the compressor from draining and running all the time in the event there's a leak down the line at some point.

Here's a link to my setup if it helps.

http://www.garagejournal.com/forum/showthread.php?p=5396184

 

[larry_g]

Can i not, just open the drain valve for a few secs to get the moisture out, and leave it some pressure in it?

This is how you do it, just a quick blast till the air is clear.

lg
no neat sig line

 

[Richard Cranium]

They have a pull chain release valve, Use one of those, pull until you see no more water come out.

 

[pepi]

So, i know why you 'should' drain your compressor, to get the water out of it. and if you don't it could start to rust the compressor's innards.

But what about those of us that have large 30gal compressors ?

Is there any other option? Seems such as waste of energy, to drain out 30gallons of compressed air every time you go to use it.

I've just upgraded from an 8gal to a 29gal... It now takes 6mins to fill, pulling 13amps in the process.

Can i not, just open the drain valve for a few secs to get the moisture out, and leave it some pressure in it? Or does every last bit of air HAVE to come every night. I may only need to fire it up once a week, if that !

Or is there a special drain valve that just somehow gets the water out, and keeps the dry air in ? Surely gravity sees the water reach the bottom of the tank, and opening (along with the pressure expelling) takes most of the water out, within the first sec or two of opening.

Do they say drain every day just to be over cautious?

This is not a serious question is it really, you actually need to be told an answer?

Put down the tools and step away, you're going to hurt yourself..

 

[sberry]

I drain it when I read a thread on it if I think about it. Leave it in long enough and it will fill up the tank. I piped it out and it was worth it, it gets done more when its easier. This ranks up with holes in the welding benches and blanch grinding for a home shop, the compulsive worry is on about the same level.
I go a month sometimes when work is light, a week if we are doing auto body.

 

[fnieto]

Install a auto drain and forget it. I have mine set for 40 min and 2 seconds of duration. Its all plumbed to the outside and hardly heard.
The parts on eBay run under $40 and can be wired to the compressor or switch.

 

[lakeroadster]

This is not a serious question is it really, you actually need to be told an answer?

Put down the tools and step away, you're going to hurt yourself..

What's wrong with the question?

Everybody starts somewhere, the only dumb questions are the questions you don't ask.

 

[G_P]

Just crack the drain valve open until it stops blowing water. No need at all to vent the whole tank full of air. I have a 20gal and it usually only blows out a tiny amount of water and I only have to have the valve partially open for a few seconds at most.

 

[Richard Cranium]

I guess I will go drain mine, now that we are talking about it.

 

[53chevy5]

Mine will have to wait till sping. My compressor is in the cold storage side of my shop and the ball valve on the bottom gets froze pretty early in the winter.

 

[Richard Cranium]

Well it has been over a month sense I have drained it got a little less then a inch of water into a pint fruit jar, I don't think that was much. Is it?

 

[CNGsaves]

Yes, it's good HABIT to learn to drain just the moisture every day if possible.

I've got small 4 gal twin tank DeWalt compressor that I use for projects where I need a nailer, portable air away from home, etc. It has a dump port on each tank in obscure position to drain each tank so it's kind of a pain.

Well, I was lazy for a few days of not draining the moisture so when I did dump it there was some rusty water that left it's mark on driveway where I dumped the water from tanks.

Now this thread is prompting me to rig up better/easier method so I actually WILL drain tank moisture every day when using that little compressor. I like the kitty litter puke tank idea above with the Folgers can !!

 

[2oolhound]

The thing is the air coming out of the compressor is hotter than the ambient air pressure so condensation forms throughout the inside of the tank on all surfaces until the temps inside and out are equal. We have an 80 gal tank at work that's equipped with an auto drain valve. It gets drained totally at the end of each day with the drain valve left open. The tank is 20 years old and solid as a rock. I have the same system on my 60 gal at home but I don't need to get 20 years out of the tank. I do a lot of sand blasting, die grinding etc so the compressor runs on overdrive a lot of the time. I don't consider the draining off at the end of the day to be a big loss, just the cost of doing work. It's only a small fraction compared to the daily usage.

Some of the new off shore compressors have pretty thin tanks though so who's to say how long they'll last before rusting through. Just pick them up and tap on them to see for yourself.

 

[^&right]

I run one of these with a 1/4" brass pipe out the wall. That and a TP tools filter/reg kit keeps things up to snuff.

http://www.amazon.com/dp/B00273WV78/?tag=atomicindus08-20

 

[thedoc46]

I run one of these with a 1/4" brass pipe out the wall. That and a TP tools filter/reg kit keeps things up to snuff.

http://www.amazon.com/dp/B00273WV78/?tag=atomicindus08-20

So this device basically just opens the drain valve for a few secs a day, then closes it?

Enough for it to get the moisture out?

What about 2oolhound's comments? with temps needing to be equal otherwise moisture will build regardless. While i appreciate the few secs trick isn't probably as effective as draining the entire tank, do we all agree its a acceptable compromise ?

Has anyone ever done any conclusive tests as in cut a tank open after a yr, of just using the 3 sec trick, to see how much corrosion there is, vs a cut opened tank that's been drained every day, and recharged everyday.

 

[lakeroadster]

While i appreciate the few secs trick isn't probably as effective as draining the entire tank, do we all agree its a acceptable compromise ?........

Has anyone ever done any conclusive tests as in cut a tank open after a yr, of just using the 3 sec trick, to see how much corrosion there is, vs a cut opened tank that's been drained every day, and recharged everyday.

To many variables: Relative humidity at the location, how often the tank was drained, materials of construction, type of compressor (different styles generate different heat profiles) yadda, yadda, yadda.

I guess I don't understand the big deal. Put a ball valve on the tank drain, open the valve at the end of each days use, when the water stops coming out close the valve.

As for everybody agreeing... that'll never happen.

It Ain't Rocket Science.

 

[thedoc46]

To many variables: Relative humidity at the location, how often the tank was drained, materials of construction, type of compressor (different styles generate different heat profiles) yadda, yadda, yadda.

I guess I don't understand the big deal. Put a ball valve on the tank drain, open the valve at the end of each days use, when the water stops coming out close the valve.

As for everybody agreeing... that'll never happen.

It Ain't Rocket Science.

I guess that was the answer i was probably already expecting. I live in SW Florida, which probably has the highest humidity in continental USA. For me, while still new to this 30gal compressor, on my old small compressor, most of the moisture seem to come out right at the end when all the air was expelled. Not an expert in this, but moisture is moisture. It's going to start the rust reaction on steel regardless of how much moisture there is. Either there's moisture or no moisture. The air contains moisture., no matter what you do. People that NEVER drain their compressors can eventually fill the entire tank with water.

I think i'm going to settle for opening the drain valve for a few secs every couple of days to get 'some' of the water out. Then say, maybe once a month drain it entirely to get most of it out. I'm only talking about a Harbor Freight Central Pneumatic 61489, which only cost me $360. So something will probably fail motorwise, and it cheaper to replace the entire thing before the tank ever rusts itself from the inside out, to the point of it being dangerous, ever occurs.

 

[mjoekingz28]

Also, be sure to open the drain valve fully.


I am not sure if draining from a higher psi will get more water out, but I think opening the valve up all the way will get more.

 

[Yv.]

I usually just drain the water out of the tank (not all the air) unless I am not going to be using the compressor for a while.

 

[thedoc46]

One thing i recommend is always having a pair of ear muffs handy when opening those valves. The sound of whistling air, can be very loud, and damage your ears. I made that mistake ONCE and ONCE only ! my ears were ringing all night as a result. I also use a glove, cos it felt almost like it was going to cut my hand !

 

[BMWED]

I ran a 1/4" plastic line from the bottom of my 80 gallon tank to a drain with a shut off valve near the end. Coiled up some of the tubing at the tank bottom so it fills up with water rather tan staying in the tank. Just open the valve and the tank pressure forces the water out.

 

[FMC1959]

Probably most will disagree with my method, I have drained my 30 gallon tank about 5-6 times over the past 25 years. Someone told me they put Prestone in their tank, so I did the same. I put a little more than half a gallon and change it once every 5 years or so.

 

[Tucker99]

Bringing this back to the top. So FMC you pour a bit of straight or diluted antifreeze into your tank? I would think adding 1/2 gal would cause some to get sucked into the check valve, pressure switch and regulator. Maybe it does and it just acts as a lubricant. What does it look like when you change it?

 

[turbowoodworker]

I am installing my black pipe and took the opportunity to look inside the tank with my borescope. I was amazed at how clean it was as I am not religious about emptying it. But threads like this are always a reminder to do so.

 

[hammlm]

Have to Chime in here.

I bought a Quincy QTS-3 20 Gallon Single Phase compressor in 1999. I used it in my hobby pursuits and recreationally since then. It could go a few weeks without use, but then be used daily for months at a time.

When it was new, I drained it diligently. Then I got an autodrain and just assumed it was doing its job. Then (probably in 2005/6) the autodrain broke and I drained it manually. But not much. And more importantly, not enough. When I would drain it, seemingly little would come out (an ounce or two).

Imagine my surprise when last month, I was wheeling it around and I heard "hiss". I assumed some connection was leaking, so I disconnected the short hose, and checked around.

Sound was coming from the bottom, so I assumed I hadn't tightened the drain valve the whole way. As I reached under to the valve I felt a stream of air coming from the weld seam. I wanted to cry.

All because of my laziness and stupidity. I was totally shocked. I didn't use it hard --- I did drain it sometimes --- it never drained a quart of water or anything....I was completely surprised.

So, I went out and bought a new compressor the next day. I need to get an auto drain hooked up.

Watch here for the quincy becoming available as I am going to put it up for grabs sometime soon to GJ guys.

Moral of the story: Drain it. Even if its a pain in the ***.

 

[mjoekingz28]

I dont the worry about draining often.

If you work at a shop and, I dunno, 4-10 guys work there and use common air, then they last guy to leave can twist the drain as he leaves. The next morning, the first guy to work can close the valve and start the compressor.


At home, when you are done with air for the day, turn the valve and bleed out the air, close valve, unplug, and then it is ready for whenever you need it again.


The only problem I can foresee it stressing. Like the guy here who finally used his 9mm socket after 20 years and it broke easy. I do not know if the compressor tank manufacturers build it to hold air continually, or expect it to 'relax' when not in use and to hold zero pressure.

 

[Tucker99]

For personal use I always have pressure in the tank. Airing up tires, cleaning vacuum cleaner filters, etc. Plug the thing in about once a week. That's why I'm interest in adding antifreeze if that works. Great idea assuming it doesn't get into air tools and compressor components.

 

[dacan23]

I think New Orleans area takes that honor.

I live in SW Florida, which probably has the highest humidity in continental USA.