Air line water separator......

[odie]

I am in need of a good method of eliminating water from compressor air.

I found this one from Harbor Freight, and was wondering if anyone has any comments.....or suggestions.

http://search.harborfreight.com/cpisearch/web/search.do?keyword=water+separator&Submit=Go

Thank you......

ooc

 

[Gil Jones]

This one may cost a bit more, but I think it will perform much better for water removal.
http://www.amazon.com/Campbell-Hausfeld-PA2121-Standard-Filters/dp/B0000CBINA/ref=pd_cp_hi_0
Gil

edit: drain your air tank of water at least once a week.

 

[Steve Worcester]

Eliminate is not inexpensive, but what are you trying to accomplish? Are you trying to get dry air to spray finish with or trying to get some water out of the lines that you use to blow air into hollow forms, etc?

The first one is quite a bit more expensive than the second. For the second, draining the tank and using a separator like the Campbell will help.

For shooting finish, I would use at a minimum, a separator and a desiccant, and better would be something like this

http://www.autorefinishdevilbiss.com/products.php?pg=413

It will get the air near bone dry will no contaminants, providing the air line isn't degraded.

 

[odie]

Thanks Gil and Steve.......

(Steve: I didn't see a price on the Devilbiss)

OK, maybe I should explain in a little more detail where I am at this point......

I had an inline water separator on my old 20gal/2hp compressor, but it never worked to my satisfaction. You can see it here in this photo, attached to the outlet at the compressor. I believe this unit was purchased at NAPA. I sold this compressor and never bothered to take it off. (Wish I had!:mad

My new Campbell Hausfield (Husky, Home Depot label) 80gal compressor works for quite awhile longer, but eventually water is accumulated in the airline. I'm not sure what is happening, but I'm guessing there is condensation within the hose, between the connection at the compressor, and my air supply outlet at the lathe. (Tank is drained/purged regularly)

It is my intent to get another water separator and install it at the lathe connection, instead of at the compressor. If my theory about the water condensation sourced within the hose itself, this should eliminate that possibility.

OK.....that's where I'm at with this.

If there are any more thoughts, recommendations, comments......I'd be glad to hear them.......

thanks

ooc

 

[Vaughn]

Lots of ways to get drier air out the end of the hose. Putting a separator close to the outlet is a good idea. Running hard lines (steel or copper) with a few strategically-placed drops can helps, too. You can even build a "drying rack" with a circuit of pipe that allows the condensation to fall out of the air before it reaches the outlet. I used a combination of all three things, plus a desiccant cartridge dryer near the outlet.

Here's the drying rack. It's 3/4" pipe. The air enters at the valve on the right (to the left of the shop rooster), then it zigs and zags up and down the loops and exits at the top, where you see a temporarily-mounted pressure gauge. (This pic was taken before I ran the overhead pipe.) The vertical drops at the bottoms of the loops capture condensed moisture, and that moisture is vented out the horizontal pipe at the bottom. There are check valves on each of these legs to allow only one-way flow out these drop legs. (A more thorough discussion and debate about the design is over on the Hotrodders.com forum here. The final results proved the naysayers wrong.)



A shot of the check valves...



Here's the drying rack hiding behind the clamp rack that covers it...



And a shot with the compressor and overhead piping in place. Although it's not real apparent in this pic, there's a 3/4" hose connection between the compressor and the drying rack...



And at the air station next to the lathe (and also my finish spraying area), I've got a variety of regulators, separators, the desiccant dryer, and a good old-fashioned moisture drop (the ball valve at the lower left corner). BTW, the desiccant dryer lists for about $900 as I recall...I bought it barely used on eBay for about $50. The red hose on the left is the flex line that connects the air station (which is attached to the side of a rolling cabinet) to the rigid overhead air lines. The little filter.separators on the right are from Harbor Freight. They are junk and I don't recommend them. I've removed one completely because it wouldn't open up to full pressure. I use that line for my blow nozzle. The other regulator leaks when it's in use, but it still holds the correct pressure. Someday I'll replace them, but it's not a priority right now. (The one that's there works fine for my pneumatic sander, and I have another regulator on my spray gun, as well as a "master" regulator near the compressor.)



My system is overkill for most turning needs, but when I got my compressor I figured it'd be a waste to have a good compressor with a bad air delivery system, so I spent the extra bucks to do it up nice. The end result is that I get very dry air out of the hose. Hopefully this'll give you a few ideas to work with.

 

[lark leazar]

I'm not an expert on setting up a home system, but we do use dry air in the laboratory at work and so I do have some experience here. I'd say you need the trap on the bottom of the compressor that opens and releases the water when some is present. This work using a float. Then just downstream of the compressor, you need a second trap that works just like the one on the compressor. Then you need a filter style trap, then finally one or more dessicant style traps. We'd finish up with a trap that has indicating dessicant, so we'd know when to change the upstream dessicant. This will get you most of the way there. If this isn't enough, the style that cool the air and then drop the water in a dead leg may be better.

 

[odie]

Lots of ways to get drier air out the end of the hose. Putting a separator close to the outlet is a good idea. Running hard lines (steel or copper) with a few strategically-placed drops can helps, too. You can even build a "drying rack" with a circuit of pipe that allows the condensation to fall out of the air before it reaches the outlet. I used a combination of all three things, plus a desiccant cartridge dryer near the outlet.

Here's the drying rack. It's 3/4" pipe. The air enters at the valve on the right (to the left of the shop rooster), then it zigs and zags up and down the loops and exits at the top, where you see a temporarily-mounted pressure gauge. (This pic was taken before I ran the overhead pipe.) The vertical drops at the bottoms of the loops capture condensed moisture, and that moisture is vented out the horizontal pipe at the bottom. There are check valves on each of these legs to allow only one-way flow out these drop legs. (A more thorough discussion and debate about the design is over on the Hotrodders.com forum here. The final results proved the naysayers wrong.)

View attachment 3373

A shot of the check valves...

View attachment 3375

Here's the drying rack hiding behind the clamp rack that covers it...

View attachment 3376

And a shot with the compressor and overhead piping in place. Although it's not real apparent in this pic, there's a 3/4" hose connection between the compressor and the drying rack...

View attachment 3377

And at the air station next to the lathe (and also my finish spraying area), I've got a variety of regulators, separators, the desiccant dryer, and a good old-fashioned moisture drop (the ball valve at the lower left corner). BTW, the desiccant dryer lists for about $900 as I recall...I bought it barely used on eBay for about $50. The red hose on the left is the flex line that connects the air station (which is attached to the side of a rolling cabinet) to the rigid overhead air lines. The little filter.separators on the right are from Harbor Freight. They are junk and I don't recommend them. I've removed one completely because it wouldn't open up to full pressure. I use that line for my blow nozzle. The other regulator leaks when it's in use, but it still holds the correct pressure. Someday I'll replace them, but it's not a priority right now. (The one that's there works fine for my pneumatic sander, and I have another regulator on my spray gun, as well as a "master" regulator near the compressor.)

View attachment 3374

My system is overkill for most turning needs, but when I got my compressor I figured it'd be a waste to have a good compressor with a bad air delivery system, so I spent the extra bucks to do it up nice. The end result is that I get very dry air out of the hose. Hopefully this'll give you a few ideas to work with.

Vaughn.......

Thanks for responding.

Wow! Wow! Wow!

That is a very creative way to deal with water in the compressed air. I have sat here and studied your drop tubes, and have become very impressed with you! I do have one question, though: Is there any particular reason why you suggest steel or copper tubing? My first thought about this would be the metal would serve to increase any internal condensation in the lines themselves......and, this is probably the point. Why couldn't PVC piping serve the same purpose?

I am working on the theory that much of the water in the pneumatic lines are likely to be from warm air constantly on the move through the lines......don't know if that's true, or not. I do know that I had an air separator on my old compressor, and had water in the air at the outlet. It is for certain that condensation does occur within the tank, but most of that runs down the side and out the purge valve.

I believe you're right that your system might be overkill for woodturning in general. Basically, all that is needed is dry air for removing chips and dust. In my case, I am running a pneumatic random orbital sander at the lathe, plus have quite a few pneumatic tools for other purposes. I don't need "spray paint dry", but nonetheless, DO NEED an air supply that is relatively free of moisture content.

Thank you very much, Vaughn........you have given me quite an uptick in my knowledge of such things.......:cool2:

ooc

 

[odie]

I'm not an expert on setting up a home system, but we do use dry air in the laboratory at work and so I do have some experience here. I'd say you need the trap on the bottom of the compressor that opens and releases the water when some is present. This work using a float. Then just downstream of the compressor, you need a second trap that works just like the one on the compressor. Then you need a filter style trap, then finally one or more dessicant style traps. We'd finish up with a trap that has indicating dessicant, so we'd know when to change the upstream dessicant. This will get you most of the way there. If this isn't enough, the style that cool the air and then drop the water in a dead leg may be better.

Hello Lark......

It's standard equipment for compressors to have a purge valve at the bottom of the storage tank, but they don't normally use a float release......they are manual. Most people don't use it as often as they should, and I have gotten better about it, as I have come to realize the importance of doing the daily drain!

......still absorbing the rest of your post......

ooc

 

[MichaelMouse]

I'm not an expert on setting up a home system, but we do use dry air in the laboratory at work and so I do have some experience here. I'd say you need the trap on the bottom of the compressor that opens and releases the water when some is present. This work using a float. Then just downstream of the compressor, you need a second trap that works just like the one on the compressor. Then you need a filter style trap, then finally one or more dessicant style traps. We'd finish up with a trap that has indicating dessicant, so we'd know when to change the upstream dessicant. This will get you most of the way there. If this isn't enough, the style that cool the air and then drop the water in a dead leg may be better.

Got to love science over speculation! The biggest help is cooling the incoming air below the dewpoint, allowing the condensation to drop out. Lowers the absolute humidity of the air going to the cylinder the way bringing in cold combustion air lowers the humidity of the house in winter. When there's less water available downstream, those dessicants work so much better.

Compressing builds heat, and, as we know, warmer air can carry more moisture. Releasing the pressure cools it. Makes HVLP look a better deal when you have to spray in conditions of high absolute humidity.

 

[Steve Worcester]

(Steve: I didn't see a price on the Devilbiss)

It's about $400-$600, but if you aren't spraying, putting a separator and a debris trap in line should work for what you need. Also change out air hose every year or two so the rubber doesn't degrade and spit chunks into the air.

 

[Robert Manning]

Odie, why don't you try bringing in some of that cold dry Montana air to your compressor inlet?

I have heard from a good source that you can use pvc pipe and it will work. It may not condense as well as copper, but you're not in Florida, either. There is a risk of the PVC shattering if it is over-pressurized or receives an impact while pressurized. I would avoid PVC that sat out in the sun and has become brittle. The UV-resistant gray PVC is also available.

Here are some pros and cons on PVC. Like woodturning, it can be dangerous:
http://bbs.homeshopmachinist.net/showthread.php?t=33892
http://www.woodweb.com/knowledge_base/Compressed_air_delivery_system.html

 

[odie]

Odie, why don't you try bringing in some of that cold dry Montana air to your compressor inlet?

I have heard from a good source that you can use pvc pipe and it will work. It may not condense as well as copper, but you're not in Florida, either. There is a risk of the PVC shattering if it is over-pressurized or receives an impact while pressurized. I would avoid PVC that sat out in the sun and has become brittle. The UV-resistant gray PVC is also available.

Thanks to Robert, MM and Steve for input......


I did have a water separator unit on my old compressor, but was installed at the compressor outlet, rather than down-line at/near the point of use......and, that was likely the reason why it wasn't working for me.

The old compressor was a 20gal/2hp unit.....and the new one is an 80gal/4hp. From having the experience of owning and using both compressors, the facts are that the newer compressor does accumulate water down line, but it takes a much longer time for that to occur. From this, I can deduct that it's not the air source that is causing the condensation.......IT'S THE HEAT! With the 80gal compressor, it just takes that much longer for the heated air to reach a temperature where the condensation can become a problem. There's not much that can be done to eliminate the heat......that's what compressors do! What is needed is a way to eliminate condensation that accumulates down line.

What has been suggested in this thread are different ways of capturing water that condensates from the compressor outlet to the point of use.....desiccants, capture chambers, filters, and so forth.

At this point, I think my plans are to get another water separator unit and install at the point of use. If I have to, I'll consider making up a pipe unit similar to what Vaughn has made up, or one of the more expensive filtering units.......but, it would be wasted money and effort to do everything, when a basic water separator unit may very well be the cure for my needs.

ooc

 

[Vaughn]

Odie, a lot of folks recommend strongly against using PVC for air lines. The primary danger is that if they fail, they shatter instead of just splitting like metal lines do. They can become very dangerous shrapnel. If you want to see a heated discussion, search an auto repair forum (like hotrodders.com) for "pvc air lines". They make the "carbide scraper" threads here pale in comparison.

Michael's right about the need to cool the air to remove the moisture. For your needs, I'm guessing that just adding another separator near your outlet will catch the vast majority of the moisture that collects in your hose.

 

[hughie]

Odie,

You pretty well get what you pay for and at some point theres got to be a cut off $$ versus need etc

K.I.S.S. is the way to go. If you can mount one on the drain plug of your air receiver and have you hose run up hill to your lathe. Then you will have a bout the simplest system around and very little water will get to the lathe.

Most of if not all of your water will collected in your air receiver, what ever is missed will run back and be drained off automatically.

What ever you get, get one that is automatic with a manual override. As when the compressor ages some. It will lose a bit of oil here and there and this will clog your auto drain set up.

 

[George Clark]

Odie, The long and short of it is you've got to cool the air to get the water vapor to condense. As long as the air is still hot from compression the water vapor will pass right through a water separator and condense when it is cooled by expansion as it exits the air tool. In my youth I used to port cylinder heads. In my first attempt, I was using a an air hose straight off my 60 gallon compressor. Very quickly my die grinder would be spitting water. I installed a water separator at the compressor but the die grinder still spit a lot of water with continuous use. I built radiator similar to, but not nearly as elaborate as, Vaughn's and the problem was solved.

In my current garage/shop I ran 3/4" black pipe around the perimeter of the ceiling with the first drop being about 50 pipe ft from the compressor. Although I have traps and water separators an each drop I get virtually no water in them. The vast majority of the water condenses out in that first 50 ft of black pipe and drains back into the compressor tank which I drain on a regular basis.

TP tools has some helpful information on air line plumbing.

http://www.tptools.com/p/2035,110_Modular-Metal-Piping-Kits.html

I hope this is of some value.
George

 

[John King]

Mini Inline Desiccant Drier

These driers may be useful in your system. - John

Northern Tool & Supply
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200319833_200319833

Harbor Freight
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94733

 

[rjones]

simple fix is to use larger air lines. if you are moving a lot of air as in air tools a small air hose is too small to keep up with the volume creates heat causes condisation. Run 1" metal lines for the long runs and put pee traps in them with drain at the pee trap.This will help some what but the only way to get dry air is to install a refrigerated air dryer Grainger sell some small good ones. Also runing you air lines in a loop around the shop with drops were you need them and then tee back in to the tank keep the air circulating. Some of the things we used in the shop to help. we had to have very dry air for the controls on the cnc machine so we used the refrigerated air dryer.

 

[odie]

Thanks for these posts......I have things to do this evening and may not get to absorb some of the information here for a couple days.

Thank you......

ooc

 

[Michaels]

Vaughn.......

Wow! Wow! Wow!
ooc

+1

Most impressive Vaughn! I bet that works very, very well indeed. That's just got to be the most clever, dessicant free system I've ever seen. I guess I haven't paid close enough attention at the hot rodding forums

Thanks for sharing and I hope you don't mind if I steal some of that for my own system!

michael

 

[Vaughn]

+1

Most impressive Vaughn! I bet that works very, very well indeed. That's just got to be the most clever, dessicant free system I've ever seen. I guess I haven't paid close enough attention at the hot rodding forums

Thanks for sharing and I hope you don't mind if I steal some of that for my own system!

michael

Thanks Michael. Steal away. My system was a conglomeration of a few other ideas I saw around the 'net. The check valve trick was the only real original idea of mine. A lot of guys just put a 12" drop at the bottom of each loop then end each with a ball valve to bleed the water out. In my case, they would have been hard to reach, so I did the collector pipe at the bottom and ran it to a place I can get to, where it's terminated with a ball valve. The drying/cooling loops get virtually all the moisture that makes it out of the tank, even when I'm sanding and running the compressor for relatively long periods of time.

And mine's not quite desiccant-free. The big blue canister thing near the main outlets is a desiccant, but it hasn't seen enough moisture in nearly two years of use to even start changing the color of the drying media.

 

[Robert Manning]

The drying/cooling loops get virtually all the moisture that makes it out of the tank, even when I'm sanding and running the compressor for relatively long periods of time.

The big blue canister thing near the main outlets is a desiccant, but it hasn't seen enough moisture in nearly two years of use to even start changing the color of the drying media.

Nice work, Vaughn.

I'm putting a copper loop system on my list of things to build. Copper is so easy to solder, even a plumber can do it.

Odie, It looks like you're on the right track. I talked to my dad and he says his moisture trap/regulator won't work if it's on the compressor. He has it located ten feet away where it works well enough for spraying lacquer on cabinets without a loop system.

 

[odie]

Odie, It looks like you're on the right track. I talked to my dad and he says his moisture trap/regulator won't work if it's on the compressor. He has it located ten feet away where it works well enough for spraying lacquer on cabinets without a loop system.

Hello Robert + all.......

This evening, I installed a water separator/filter unit very similar to the Campbell-Hausfield unit Gill Jones showed us in post #2 of this thread. I mounted it to the back side of the lathe.

Robert, I think you are probably right......I suspect this is all I'll really need, but only time will provide confirmation.

If this isn't enough to keep from spitting H20 after a period of time.......I have some very good ideas here for improving my air system.

Thanks, to everyone, especially Vaughn for all the input here.

ooc

 

[Robert Manning]

Odie, post #65 on this site is very informative as to how the water is condensed and captured. Post #68 is worth looking at to prolong your compressor tank's life.

http://bbs.homeshopmachinist.net/showthread.php?t=33892&page=7

 

[waltben]

I've been following this post with interest, although I haven't had a serious problem with moisture and certainly DO NOT want to prolong the life of my ten+ year old oil-less NOISY compressor. (In fact, I'm doing my best to push it on down the road to the junk yard so I can get something much quieter.) I'll have to clean out a spot near a wall for the new one so as to put a loop on it for certain. My question for Vaughn and everyone is: Do you have your regulator at the end of the line (service point) or at the compressor (Post 65 recommendation)? With the layout of my shop, I'd have to compromise and put my regulator at the end of the pipe loop, then a separator, then run pipe up and across the ceiling with a couple reels hung from it (my shop is a 2 1/2 car garage with a single big door). Any comments on this?

 

[Michaels]

Generally the main line is regulated at the compressor to a pressure 10-20lbs higher than what you'll want at the drop.

Then you add a smaller drop specific regulator for the connection you're using. This reduces the pressure loss that happens when a tool is first used. Think of air like water (simplifying the analogy) and when you quickly remove a holding wall, the pressure closest to the wall takes a bit to equalize with the rest of the line - like a dam breaking and the water level being lower right at the break.

By having the regulator right at the drop, you really only have to equalize the hose you've got connected to the tool vs. the entire line all the way back.

FYI, my compressor has the main lines set to 120 and I regulate to 90 (or less) at the tool drops.

I suspect another can articulate this better than I, hopefully the point was conveyed though.

Michael

 

[Robert Manning]

With the layout of my shop, I'd have to compromise and put my regulator at the end of the pipe loop, then a separator, then run pipe up and across the ceiling with a couple reels hung from it (my shop is a 2 1/2 car garage with a single big door). Any comments on this?

Generally the main line is regulated at the compressor to a pressure 10-20lbs higher than what you'll want at the drop.

What post #65 explains, is to cool the warm and moist compressed air from the compressor which causes the H2O to condense, then separate the condensed moisture with the separator at the full pressure you are generating, and then finally reduce the pressure with your regulator to your working pressure.

When I first viewed this discussion, I was interested from the standpoint of spraying the ultimate finish and this caused me to seek a full understanding as to the process of compressing and drying air. During this quest, I happened on to an article about filling SCUBA tanks with dry breathable air. I found the following lengthy article to give a very advanced understanding of the process of compressing and drying air. Keep in mind that a SCUBA diver at depth would be breathing many more cubic feet of air per breath than at the surface, due to the increased pressure.

http://www.neptunoworld.com/articles/compressors.html

 

[waltben]

Generally the main line is regulated at the compressor to a pressure 10-20lbs higher than what you'll want at the drop.

Haven't the time right now to read the scuba document, but external Post says to cool and condense water out before regulating. I agree that all compressor makers stick the regulator right on the output, but that's not where it really should be according to what seems to me makes perfect sense. My shop layout doesn't let me do things perfectly, but I can at least get most of the way there.

 

[Vaughn]

...My question for Vaughn and everyone is: Do you have your regulator at the end of the line (service point) or at the compressor (Post 65 recommendation)?...

Walt, I've got my main regulator (3/4" input/output) at the beginning of my cooling loop. Based on the post Robert mentioned, it looks like it'd be more ideal to have it at the end of the cooling loop instead. I've also got a small regulator/separator at the 'air station' right by my lathe. The main regulator is set at about 135 psi and the small one is usually at about 85 or 90 psi for my sander. The air station has two separate outlets, so I can have both the sander and a blow nozzle at the lathe. I did have a regulator/separator on the blow nozzle line, but it was leaking so I removed it. I always ran the nozzle at wide open pressure anyway, and the separator wasn't seeing any moisture by that point in the line, so I haven't gotten around to replacing the broken regulator.

 

[GA Darling]

I have read all the post in this thread. Some very good ideas for removing water from the air system are noted. However, one very simple yet so very important procedure has not been mentioned where loop systems around the shop are concerned. When plumbing your drops to a location, take the air off the top of the air line. In other words, place your tee pointing upward. This may sound silly but it alone can save you a lot of water problems.

Greg