air dryer for compressed air system

[ArTrvlr]

Don't know how you feel about Harbor Freight stuff, most folks love it or hate it... but they sell a refrigerated air dryer. Harbor Freight Tools - Quality Tools at the Lowest Prices. They sometimes have it on sale for 299.

They also have a desiccant dryer (97686) Harbor Freight Tools - Quality Tools at the Lowest Priceswith replaceable disiccant 97924Harbor Freight Tools - Quality Tools at the Lowest Prices. Not sure if that can be dried or not.

I have no experience with any of these items, so can't comment on quality. I will strongly advise NOT to waste you money on their automatic compressor drain kit Harbor Freight Tools - Quality Tools at the Lowest Prices. I bought one and exchanged it two times trying to get one that didn't leak. I finally just returned it for a refund. Now I am considering a timer based tank drain like mentioned in an earlier post. I have been trying to find one for less than $100 range, but no luck. I may have to bite the bullet and get one at that price, because I believe keeping the tank dry is the first step to having dry air. As well as longer tank life.
jp

 

[SpringHollow]

Ingersoll Rand ADV Drain Valve - i have bought these for $50 new on Ebay. That is why i say it is not worth making your own.

Ken

 

[Ken_CT]

I have a different take on auto drain valves. Don't use them. I have seen systems that have an auto drain, where the auto drain has stopped operating, and were half filled with water. With a manual valve, one learns to drain it every so often, and as long as it is done, everything is fine. If an auto drain clogs or for any reason fails, one takes for granted it is working, and water accumulates in the vessel.

This advice is worth every penny you paid for it.

 

[ArTrvlr]

I have a different take on auto drain valves. Don't use them. I have seen systems that have an auto drain, where the auto drain has stopped operating, and were half filled with water. With a manual valve, one learns to drain it every so often, and as long as it is done, everything is fine. If an auto drain clogs or for any reason fails, one takes for granted it is working, and water accumulates in the vessel.

This advice is worth every penny you paid for it.

Ken, thanks for your thoughts, I do not feel overcharged

One reason I have been considering an auto drain valve is I plan to relocate my compressor outside my shop and felt I wouldn't drain it as often since it will be sorta out of the way. (on the back side of the shop) I have taken what you said about reliability (along with my naturally cheap nature) and have decided to use a remote, cable operated valve, (like this: Pneumatic Drain Valve )with the cable through the wall of the shop so I can drain it when I think about it without going outside. Not that I am too lazy to walk outside, it will just be much quicker to just pull the cable when I think about it, and keep on working.

Thanks for helping me arrive at this lower cost (sounds better than cheap), more reliable (at least as reliable as my memory... uh-oh, may be a problem) solution.
jp

 

[DieselPower]

jimg, I've priced one with a water sensor and it was pretty high priced. Think I could build one alot cheaper, but the problem is finding the water sensor at a cheap price. Any ideas on that?

Just stop by any heavy truck dealer and ask for a coolant level sensor. Get one for a 90's vintage truck, they should be cheaper than the ones for newer trucks. They come in NO (normally open) and NC (normally closed) types.

They can't handle a high current flow so simply use the coolant sensor to activate a relay that would in turn open the pneumatic valve. You can usually pick up a pneumatic valve on ebay very cheap. I have purchased dozens of them off ebay over the years for projects.

As far as the automatic drain valves go I have a couple I have gotten from Snap On tools over the years. They are kind of fail safe. You run a line from the unloader circuit to the valve and it purges every time the compressor reaches cut out pressure. They operate off of air pressure by means of a pneumatic piston that opens and closes the valve.

 

[Ken_CT]

As far as the automatic drain valves go I have a couple I have gotten from Snap On tools over the years. They are kind of fail safe.

I have no doubt they they are high quality valves, but if the valve fails, it will fail to the safe or closed position, and the operator may not know the valve has failed. One could install a sensor with alarm in the tank, but I have always been a fan of the KISS (keep it simple, stupid) principle. Complicated doesn't always mean better.

The probability of anything mechanical failing is 100%, the variable is time.

 

[SpringHollow]

That's why i do both. The automatic are nice when doing large jobs like sandblasting. It is humid here in the summer and it is nice to keep everything drained. And the rip cord style are convenient. I have also seen the foot pedal ones.

Ken

 

[Pilot]

The recommendations are mostly way overkill for what you need.

Following Sharpe's diagram on their website (Sharpe makes spray equipment) I ran a 2' long hose from my 60 gal compressor to a vertical copper pipe on the wall. The pipe goes up the wall, about 24 feet along the garage wall, down about 3 ft., then back toward my bench for about 10 ft. Every vertical has a ball valve below it to drain. Where it ends, I have a cheapie air separator from Harbor Freight.

After hours of use, I get a little fog out of the first valve, closest to the tank, a little fog sometimes out of the one 24 feet away, and rarely get any sign of moisture at the last drop before the filter. The filter hasn't gotten any noticeable accumulation. I have used this setup for riveting on the plane I am building, running a die grinder and spraying primer and have never had any water problems.

I am in western Oregon. In spite of all our rain, it isn't that humid as most of the rain comes when it is cool and the air doesn't really hold much moisture--not like in the south or east coast. If you live in more humid areas, you might get some moisture out of the water separator.

 

[SpringHollow]

I have a vertical air compressor, then run it through a coalescing filter, through a bunch of pipe, another coalescing filter then through hose to my tools. Everything gets drained. I still get water spraying out in the summer at the end of the hose when hooking things up - typically the summers here can be quite humid.

I bought a used IR compressor cheap because it was 3-phase. Besides being more capable, it has a much better after cooler on it and the pipe runs will now be much longer to the new shop area so i hope that helps. In addition, i just purchased today a barely used (~10 hours) Sharpe 6770 membrane filter setup that someone was letting go REALLY cheap. They decided to sell it since the truck bed liner business for which they purchased it was not going to be profitable. The specs on the unit sound pretty good. Hopefully it works as advertised. If not, i do not have too much invested in it.

Ken

 

[jimg]

DP,
Thanx a million for the help. Lots of truck places around me so getting the parts should be easy.

Just stop by any heavy truck dealer and ask for a coolant level sensor. Get one for a 90's vintage truck, they should be cheaper than the ones for newer trucks. They come in NO (normally open) and NC (normally closed) types.

They can't handle a high current flow so simply use the coolant sensor to activate a relay that would in turn open the pneumatic valve. You can usually pick up a pneumatic valve on ebay very cheap. I have purchased dozens of them off ebay over the years for projects.

As far as the automatic drain valves go I have a couple I have gotten from Snap On tools over the years. They are kind of fail safe. You run a line from the unloader circuit to the valve and it purges every time the compressor reaches cut out pressure. They operate off of air pressure by means of a pneumatic piston that opens and closes the valve.