I am trying to find some information on engine oil storage tanks filter vents, we are using 500 gallon tanks in remote areas to provide engine oil to the engine through automatic level controllers.
When the storage tanks are filled there is a vent on top of the tank to release the air inside the tank. As the engine uses the oil air goes back in the tank, non-filtered and could be contaminating the oil. Does anyone recommend a filter vent that I could use? It is a 2”NPT connection.

http://www.noria.com/buyersguide/airsentry.asp

http://www.bartassociates.com/breathers.html

I have used both of these in the past and was happy with them. Currently I use the Air Sentry ones on all of my bulk storage tanks.

Do I recomend filter vents? Highly. They prevent (when you use the desiccant type) moisture contamination and particle contamination from entering your bulk oil storage tanks through the vent. Anything you can do to prevent contamination in your bulk storage, resivour systems is a plus and can help extend fluid life and equipment life.