Air Comp.-water filters

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I'm fun sized!
Apr 19, 2004
Hotel M-F, home weekends!
Some of you may have water filters on the outlet of your shop or home air compressors, where are they located in the scheme of things...coming out of the compr./at each fitting/ in the line along the wall. Reason for this is in my setup I have a small one about 3-4" on the oulet side of my compr. but am still getting quite alot of water through my air tools. I have heard that the water filters should not be at the compressor but at each air fitting? What are your setups & do you see water when using air tools?
I've got a water separator, then IR coalescing filter then regulator all at the outlet of the tank.

I think that the trick for water filters is that the air must be cool for them to work. Coming out of the pump, the water is in vapor form. If it stays in the tank for a while, it will cool and the water turn into a "fog" of water droplets suspended in the air, and maybe even droping onto the walls of the tank (this can all be separated out). But, if the compressor is maxed out and the air dosn't cool in the tank, the air will go right by the water filter in vapor form (as a gas). It will then mist out as the air cools in your tool or, even worse, your spray gun.
Compressing air heats it allowing it to more easily carry water, on the other end the air expanding going through the tool cools the air causing the water to fall out. A separator at the compressor is mostly worthless, the air is still hot and not much is trapped, most separator manufactures recommend at least 30' of hard line between the compressor and separator. Simple drops, (a T with line running down and a valve on the end) after hard line runs will catch a bunch of water. Separators work by expanding the air as it enters the chamber and spinning the air as it exits, the expansion turns some of the moisture into droplets and the spinning flings them into the side of the chamber so they aren't carried out. For a good separator it's bigger is better, with more chamber volume comes better efficiency and as close to the tool as possible.
Its fine having a water separator at the compressor outlet. But also need one at the end of the line if you don't want to be putting water in your tools.
Tools are us has it on the money above, AFAIC. Drops T'd in the hard airlines every so often do more to get rid of water than most any filter. I've got an 'U' shaped air system with two main branches each with three outlets at chest level for use and one overhead reel for taking air outside. I have a good filter/seperator in each of the two legs and two drops in each leg too, one at midway and the other at the ends. The two drops at line end and the bottom of the tank bleeder are the only places I ever get any water out of the valves. The bottles on the separators have never collected a single drop, summer or winter. It's been in for over three years now and that's the way it is for me. Can't say that such would be the case in every installation.
Thanks for all the good input. Now I have to go find a delaer in Jackson that has a large enough water seperator....Lowes & Depot don't.
IR refridgerated unit at compressor... 1200$ for one that can handle cooling 36 CFM to 36* or 700$ for a unit for home use.. I bet you could find a used IR Frid unit for 400$ ish.. alot yes.. but HOW much do you have in air tools? also.. one RUINed paint job could payed for the unit in materials alone not to mention the labor end of it.
Here's what I did:

I got a coil of copper line (I think it is 1/2" or 3/4" by 50') in a tub immediately after the compressor. this gives me 50' of copper line without taking up much room. My original plan was to seal the bottom of the tub where the line exits so I could fill it with bags of ice when painting, but this seems unecessary. Doing so would make for a very cheap refrigerated drier I have a large water/oil seperator immediately after this coil that has an automatic (float) drain.

For the downlegs, bring them out the top, so any water in the line will not come out. At the end of each leg I have a seperate down leg with a valve to empty out any water that collects in the line.

Those are old pics, but on the service line (the one without the valve in the middle picture) I have a regulator and water seperator.

I run a seperate line to where I do painting, and that one has a dessicant drier in addition (the last pic is the down leg leading to the paint area)
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