The tubes used in the automobile are extruded tube, continuous extrusion tube, aluminum copper composite tube, extrusion drawing tube, rolling drawing tube, welding tube and so on. The most used are:

Precision drawing tube: used for the connection of the water tank.
Porous continuous extrusion tube (Harmonica tube): used in condenser, evaporator, air cooler, etc.

Welded tube: used for the connection of the water tank.

Extrusion tube: used for water tank connection;

Coating tube: coated with coating (nylon, etc.) to improve its corrosion resistance, used in the connecting pipe at the bottom of the car.
Precision drawing tube for automobile:
Because the aluminum tube has the advantages of light weight, high thermal conductivity, good corrosion resistance, easy forming and high recovery value, it is widely applied in air conditioning pipeline, power control pipeline, fuel oil pipeline, diesel oil return pipeline and heat exchanger pipeline. The precision drawing tube also has the characteristics of small size deviation range and high surface quality.

Automobile aluminum tube alloy mainly consists of 1 series alloy, 3003 alloy, 5049 alloy, 6 series alloy (6061, 6063, 6082), etc. their state, performance and size are as follows:
The principle of selecting aluminum tubes is:

1) Formable performance, easy expansion and bending, and other molding operations.
2) High fatigue and corrosion resistance, adapted to the environment in the engine room.
3) Suitable for welding and mechanical links.
4) Long term use and good performance price ratio.

Alloy	Temper	Tension strength /N∙mm²	OD /mm	Wall thickness /mm	Features
3003,3103	O, H112, H12--H18	95~180	6~24	0.3~2	General alloy, good formability and good corrosion resistance
5049	O	180~250	9~18	0.8~2	Medium to high strength, good formability, good corrosion resistance, especially in alkaline environment
6061,6063,6082	O、T4、T6、T83	90~290	6~18	0.5~2	The strength is from low to high, the formability is good, the corrosion resistance is high, especially in the acid environment.

Harmonica tube

The harmonica tube is named because its section is very similar to the harmonica. In the process of use, the tube flows through the medium that needs to be cooled. The general hole numbers of harmonica tube is 5-25, the more can reach more than 60, the wall thickness of 0.2--1.0mm, width about 5mm, used in the manufacture of belt type condenser, the user first harmonica tube installed in the snake into special mold plate, then the wave shaped heat sink composite foil processing both sides coated solder thickness before 0.15--0.20mm belt together with the harmonica tube, then the condenser in an inert gas brazing furnace welded heat exchange system.

The size of the harmonica tube is thin and empty, and the inner cavity area is small. Henan Chalco aluminum alloy has 1035、1050 and 1070 alloy extrusion, which has good plasticity, strong mobility, moderate strength, good solderability and high corrosion resistance. The microstructure of weld tube should be no harmonica defects, cracking cold deformation, the bursting pressure is greater than or equal to ≥8N∙mm², with 5--8MN extrusion machine and. In order to improve the corrosion resistance of the tube, 3003 and 3102 alloys were selected in Henan Chalco aluminum. In order to improve the capacity of tube pressure, 6063 alloy was used.

The specifications, sizes and deviations of the harmonica tube

Specification/mm L(Width）×h(Height）	Tolerance of Outside /mm		Wall thickness and its tolerance/mm	Holes/unit
	L	h
12×6	±0.15	±0.10	（0.6-0.8）±0.05	18
100×6				16
64×6				12
48×6				10
44×6				8
32×5				8
26×5				6
22×5				6

The production process of the harmonica pipe is: smelting -- Casting -- sawing -- Heating -- extrusion -- stretching straightening -- cutting times -- shaping and correcting -- cutting times -- checking and checking -- warehousing -- shipment.

Intake manifold:

The intake manifold is a key part of the tube which is sent from the throttle to the engine. With the improvement of engine performance, the shape of the manifold is not only more complex, but also the quality is improved. Therefore, it is urgent to light weight. The new aluminum alloy tube developed in Henan Chalco aluminum alloy has been greatly improved in its function, and the effect of light weight is remarkable. The pipe wall is as thin as possible and occupies as little space as possible, usually making a smooth bending state to reduce the peer resistance of the oil vapor mixture. The 6063-H112 alloy drawing pipe is usually used, the wall thickness is 2mm, and the bending is done by the spinning stretch bending machine.

Fuel pipe:

The former fuel pipes are mostly steel or aluminum castings. They have been replaced by extruded 6063 T5 or 6061 T6 pipes. The quality is reduced, the manufacturing process is simplified, the cost is reduced, and the quality is improved.



❶Aluminium tube for air conditioning system
Alloy: 3103, 3003, 5049, 5052, 6063
Dimension: Φ8 x 1 - Φ30 x 2mm
Tolerance: OD & Thickness+/-0.05mm
Temper: O, H112, H111, H12, H14, H16, H18, H32, H34, T4, T42, T6, T83

❷ Radiator tube
Alloy: 3103, 3003
Dimension: Φ6 x 0.35 - Φ9 x 0.5mm
Tolerance: OD & Thickness+/-0.05mm
Temper：O, H111, H12, H14, H16, H18

❸Tube for pipe sleeve
Alloy: 3103, 3003, 6063, 6082, 5052
Dimension: Φ15x 1.5 - Φ25 x 2mm
Tolerance: OD & Thickness+/-0.10mm
Temper: O, H111, T4, H32, H34

❹ Tube for subcooler & muffler
Alloy: 3103, 3003, 6063, 6082, 5052
Dimension: Φ20 x 1.5 - Φ30 x 2.5mm
Tolerance: OD & Thickness+/-0.10mm
Temper: O, H111, T4, H32, H34

❺ Heat exchange tube for air cooling system of power plant, seawater desalination system and large cold storage
Alloy: 1060, 3103, 3003, 6063, 5052
Dimension: Φ16 x 0.6 - Φ50 x 5mm
Tolerance: OD & Thickness+/-0.10mm
Temper: O, H112, H111, H14, T4, H32, H34

❻ Big MPE tube for charge cooler of bus, road machinery and air cooling system of power plant
Alloy: 1100, 3103, 3003
Dimension: width 20-120mm, height 4-12mm, thickness 0.45-1.2mm
Temper: H112

❼ Tube for other industry
Alloy: 1060,1100, 2024,3103, 3003, 5052, 5083, 5056, 6005, 6060, 6063, 6061, 6082, 7003, 7005, 7022, 7075
Dimension: Φ15x 1-Φ120 x 20mm
Temper: O, H112, H111, H12, H14, H16, H18, H32, H34, T4, T6, T73, T8, T9