North Benz tells you the working principle of internal and external filter elements:
The working principle of the built-in filter element is completely different from that of the external filter element. After the external filter element is in the gasoline pump, the gasoline output of the gasoline pump is filtered by the filter paper in the external filter element, and the output of the gasoline pump has a certain pressure. The built-in filter element is placed on the input end of the gasoline pump, and the gasoline enters the gasoline pump after being filtered by the filter material in the filter screen. This kind of filter material has large volume and large filtering capacity, so its service life is relatively long.
