air compressor filter question

[mds33200]

Hi, I purchased an air filter for my air compressor, its just a small 2 gallon tank. I use it to clean dust off of electrical components so I wanted to put a filter on it. I purchased one from lowes, its a Kobalt 3/8" Air Filter. It has two holes in it, one that says in, another that says out. I hooked the hose from the compressor to the filter (marked "in") and ran another from the hose (marked "out") to the air tank. I fill the tank and air is coming out the bottom of the filter.

There is a nozzle and I assume its for when liquid collects- its like a drain I would assume? But in order for it to hold pressure, the plug on the bottom has to be pulled out. In other words if I pull the plug (its spring loaded) pressure can build up, but if I release it then the air drains right out.

Not sure if I am doing something wrong or if it is defective, the instructions dont even mention that part other then refuring to it as a drain pin. Any ideas? ps if you want to see a photo let me know and I will post one.

 

[930dreamer]

The drain should un screw to drain. It's not an auto drain is it? Post a picture.

 

[mds33200]

Hmm well that term makes sence (auto drain) because it seems to do just that. It doesnt say anything like that on the box or in the instructions however. Below are three photos, one of the whole unit, one with the valve open (default position) and the bottom shows the tip pulled out, and when I do this the air is restricted.

So in other words in order for me to hold any air in the tank, that plug has to be pulled out.

 

[930dreamer]

If I understand this correctly, are you installing the filter after the air goes into the tank or before? Best bet is to install into the air line at point of use. Just run a air line into the "in" port after the air leaves the tank and another section of air line from the "out" port. The filter doesn't appear to have a drain valve to unscrew.

 

[crashbumper]

That's an auto-drain for sure. When installed on the air hose, the pressure will close it up. As soon as you close the line at let the pressure out the drain will pop open and let out any moisture.

The only way these filters work is if you routinely let drain the line of air to let the drain open.

Also, get a desiccant filter for the very end of line near the blowgun to help catch any last bits of moisture. Filters like this can still let some past.

 

[mds33200]

Hi, thanks for the replies. That makes sense now. I now realize the problem is my compressor- it isn’t putting out enough pressure fast enough to push the plug out. For example I ran the compressor for about 5 minutes originally, only to see the pressure was under 5 PSI (because the air was shooting out the bottom drain hole). However I just tried pulling the auto drain plug out and holding it (extended) as the compressor is inflating, and I release at around 20 - 25 PSI that the pressure is high enough to hold the seal (no air leaks out).

The airtank is made to auto fill to arround 110 PSI and once the pressure drops down to around 80 PSI the compressor kicks on. So it will never "automatically drain" unless I drain it myself. However there is very little moisture accumulating (it isnt a gas powered compressor, it just plugs into the wall) so would this do the job? Or should I get another type that has a screw drain? i don’t mind manually emptying this one however, (it will take a while to fill). However if it is ineffective due to my type of compressor, I obviously want to get the correct type so any further info would be appreciated!