Principle of fuel water separator 
1. There are many methods of fuel water separation, including physical separation, chemical separation, electric flotation separation, etc.;
2. The physical separation method is a method that uses physical phenomena such as fuel water density difference or filtration and adsorption to separate fuel water. The main feature is the separation of oil and water without changing the chemical properties of the oil, including gravity separation, filtration separation, coalescence separation, air flotation separation, adsorption separation, ultrafiltration membrane separation and reverse osmosis separation, etc.;
3. The chemical separation method is to put flocculant or aggregating agent into oily sewage. Among them, the flocculant can make the oil condense into a gel and precipitate, and the aggregating agent can make the oil condense into a colloid to make it float, so as to achieve a method of fuel water separation;
4. The electro-floatation separation method is to introduce oily sewage into a tank equipped with electrodes, and use the bubbles generated by electrolysis to attach oil droplets during the floating process to separate them, thereby achieving fuel water separation. In fact, it is a physical and chemical separation method. In addition, emulsified oil can be separated by activated sludge biochemical method.

Drainage method of fuel water separator
First open the hood and place the container on the end of the vinyl hose under the drain plug of the fuel water separator. Then loosen the drain plug counterclockwise, and operate the diesel filter manual fuel pump about 10 times to drain water until the fuel water separator is full of fuel. After draining the water, tighten the drain plug clockwise, and then press the manual oil pump several times up and down.