Oil Filter

[pvcces]

Jack, think of a plug with a standing tube welded on the top of it and a big hole in the bottom of the plug.
With that inserted in the bottom of the tank, liquids collect in the bottom of the tank, and vapors blow out through the hole in the plug.

At least, that's how DD made the one that we bought off of eBay. It works good.

Tom Caffrey

[jackhartjr]

Thanks Tom, that made sense.  I was picturing something that went in from the bottom.  So apparently the vent and drain simply screws in from the top as one piece?
Jack

[pete81eaglefanasty]

 Jack, Tom, Paul
As I stated before It has only one plug on the unit, on the bottom which is the drain and vent. Here is a couple of pictures of the plug and the bottom of the tank. My son took the plug out so I'll have these pictures to show you. As you can see it has the vent up the center of the plug.

          Pete & Jean
           FANTASY

[Stan]

Obviously the design serves two purposes. It is also an overflow if you forget to drain the tank.