Protection And Assembly Of Fuel Lines
Jan 23 , 2021

Protection And Assembly Of Fuel Lines

The automobile fuel supply system is responsible for storing enough fuel and providing the engine with suitable fuel to participate in combustion according to the required working conditions, controlling NOX and particulate emissions to meet the environmental requirements of the vehicle, as well as controlling the amount of fuel supplied and the volatile emissions of fuel.The fuel line is responsible for connecting the engine and the fuel tank, and the clean fuel is input from the fuel tank to the engine, playing a vital role in the supply system.

Protection before assembly of fuel line

The fuel line requires the supplier to install dust caps on the orifice to protect it from dust, and to protect it from scratches and deformation during the transportation process, and to ensure that the protective caps on the orifice of the fuel line do not fall off before installation on site, so that it can be installed and disassembled immediately, and to ensure that no foreign objects fall into the fuel line during installation. 

Fuel line have hoses and hard lines, which are used to transport fuel from one point of the vehicle to another or from a storage tank to the vehicle. The hose is made of reinforced rubber to prevent splitting and kinking, and the outside of the hose is usually covered with a braided stainless steel tube.The material of the hard tube is stainless steel.

There are three types of fuel line connections: hard pipe to hard pipe connection, hard pipe to hose connection, and quick-plug joint connection; the pipe joints should be divided and assembled on the frame and body first according to the product drawing requirements. The arrangement of fuel pipe should be smooth, beautiful and without the phenomenon of dead bend. 

Assembly requirements for fuel line

1) Assembly requirements for connecting hard lines and hard lines

Before assembling, make sure that the inside of the line joint is clean and free of processing impurities such as flash and burrs;

When transferring, the assembly sequence should be arranged according to the process. When the line clamp is fixed, the oil line should be completely clamped into the line clamp;

The inflection point can be adjusted appropriately when the hard line is assembled

When the hard line joint is a threaded joint, the tightening torque is smaller than its breaking torque

2) Hard tube and hose connection: The connection between hard tube and hose is interference fit, and the general hose is marked with positioning marks

Before assembling, make sure that the line joints are clean and free of impurities When assembling, the hose should conform to the design trend, and there should be no twisting

Except for special requirements, the clamping position of the hoop should be in the middle of the two ports of the interconnecting line, and beyond the boss to be parallel to the line wall, evenly contact, to avoid tilting and oil leakage problems 

When the hose is connected with the line clamp, it should be ensured that it is securely locked without loosening or falling out.


The U.S. Environmental Protection Agency defines fuel lines as "all hoses or lines designed to contain liquid fuel or fuel vapor. This includes all hoses or lines used for fueling ports, for connections between dual fuel tanks, and for connecting the canister to all fuel lines. It does not include hoses or lines used to lead the crankcase vapor to the engine air intake, nor any other hoses or lines open to the atmosphere.

It is an important part of the production process control of automobile manufacturers to choose the appropriate line connection operation mode in combination with reality to ensure the reliability of the fuel line connection assembly and prevent fuel leakage at the line joint.



1. The fuel tank and fuel line should be firm and fixed firmly, and will not be damaged or leaked due to the vibration and impact of the normal driving of the vehicle

2. After the fuel management of the vehicle is assembled, the fuel system must be tested for fuel air tightness and ventilation before refueling


Only by ensuring the correct assembly of the fuel line can the normal operation of the automobile fuel supply system be ensured, which brings a sense of safety to customers' driving. 


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