Moisture/compressed air

[binfordw]

I've been dealing with moisture problems off and on for months now with my Plasma table. Last fall I think it was I purchased a "motorguard" airfilter setup after doing alot of reading. It worked great, but I still find myself having issues now and then.

* Should the paper elements be re-used/reuseable? People say they reuse them, but when I did so I wound up with moisture problems, even with a "dry" used filter. It seems like the plastic core is squished/damaged and allows moisture to pass.

I picked up a cheap $12 disposable dessicant filter and placed it right off my Hypertherm unit, (with the paper element filter in the line as well) with the intentions it would not get used up much unless the paper filter became waterlogged and was in need of change. In about 20 mins of runtime it appears to be nearly used up already lol. This was with a "reused" paper element, which apparently wasnt working correctly.


I've seen people using "auto drains" on their compressors, but Im not sure I understand why. I thought the water would separate to the bottom of the tank, and not really be a problem as long as it was emptied every few days or so. If this is true, then why do so many people reccomend installing water traps- low spots in airline with ballvalves to allow moisture to collect and be drained? If moisture can travel up and out of the tank, then it can do the same in the lines too right?

[Geof]

Originally Posted by binfordw .... If moisture can travel up and out of the tank, then it can do the same in the lines too right?

Water travels out of the tank as water vapor not liquid water. Generally the air in the tank is quite a bit warmer than room temperature so it cools as it travels through the small diameter airlines and water condenses. This is why traps are useful at the end of long runs of pipe abd why it is best to have the runs sloping so water drains toward the traps even when the air is not flowing.

[binfordw]

So if it leaves tank as vapor, why does it matter how much "liquid" water is trapped in the tank? Doesnt draining the tank- such as the auto devises are for, just remove liquid water that was collected in the bottom?

How would that effect how much moisture enters the lines?

[Geof]

You are probably correct that once the water had condensed in the tank it is not going out with the air. But when the air in the tank warms up it can cause some of the water to evaporate again. As far as I see it the auto drains are a convenience because you don't need to remember to drain the tank.