Electrostatic Treaters are used at the final sta

Electrostatic Treaters are used at the final stages.  They consist of a fire tube on one end and an electric grid on the other end. The fire tube heats the fluid and gets most of the water out which I assume is an evaporation process.  The electric grid which I assume consist of electrodes are submersed and oil polishes the rest of the water out before the oil goes to the tanks to be sold.  It is the cheapest way of treating oil.  Diagram below.  

I use a machining process sometimes called EDM'ing.  Electrical Discharge Machining.  An electrode combined in an oil bath can penetrate a block of metal and remove material.  The electrode can be machined to any shape such as a company logo and penetrate the face of the steel or stainless steel or aluminum part.