As an important part of the fuel system of modern automobiles, the fuel filter's main function is to filter out impurities and particulate matter in the fuel to ensure that the engine can receive a clean fuel supply. A high-quality fuel filter can not only improve the combustion efficiency of the fuel, but also effectively extend the service life of the engine.

1. Shell
The shell of the fuel filter is usually made of metal materials, among which the common is aluminum. Aluminum is widely used because of its light weight, high strength, corrosion resistance and good thermal conductivity. The shell of this material not only ensures the durability of the filter, but also reduces the overall weight of the car, which helps to improve fuel economy and vehicle performance. The structural design of the aluminum shell usually takes into account multiple aspects such as installation convenience, sealing and durability. The shape and size of the shell will vary depending on the model and filter type, but it is usually designed to be easy to install and remove. There will also be a special interface on the shell for connecting with other parts of the fuel system. Although the shell usually does not need to be replaced as frequently as the filter element, regular maintenance is still very necessary. Car owners can regularly check whether the outer shell is deformed, cracked or rusted, and repair or replace it in time. In addition, when replacing the filter, be careful not to damage the outer shell and the seals on it.

2. Filter element
The filter element is the core part of the fuel filter, and its filtering effect directly affects the performance of the engine and the cleanliness of the fuel. The filter element is usually made of multiple layers of filter paper, nylon cloth or polymer materials, which have filtering performance and corrosion resistance. The structural design of the filter element is also very important, and a chrysanthemum-shaped design is usually adopted to increase the flow area and filtering efficiency. The filtering accuracy of the filter element is usually between a few microns and tens of microns, which can effectively filter out impurities and particulate matter in the fuel.

3. Bracket
The bracket is one of the important structures inside the fuel filter, which is used to support and fix the filter element. The bracket is usually made of corrosion-resistant materials such as stainless steel, and has high strength and stability. There are multiple holes on the bracket so that the fuel can be filtered smoothly through the filter element. At the same time, the bracket can also prevent the filter element from being deformed or damaged during the filtering process.

4. Inlet and outlet ports
The inlet and outlet ports are the interfaces between the fuel filter and the external fuel system. The inlet port is usually located at the bottom of the filter to receive fuel from the fuel tank; the outlet port is located at the top or side of the filter to deliver filtered fuel to the engine. The design of the inlet and outlet ports needs to ensure that the fuel can flow into and out of the filter smoothly, and needs to have good sealing performance to prevent fuel leakage.

5. Other auxiliary structures
The fuel filter may also include some auxiliary structures, such as sealing rings, pressure sensors, etc. The sealing ring is used to ensure the sealing performance between the filter and the fuel system; the pressure sensor is used to monitor the fuel pressure inside the filter so that potential problems can be discovered and solved in time.