Aluminum Pipe

Extrusion die to the extrusion press
A circular die is typically crafted from h13 steel. If an appropriate die is available, it is retrieved from storage. Prior to extrusion, the die must be preheated to temperatures between 450 and 500 degrees celsius. This preheating helps extend the die's lifespan and ensures a consistent metal flow. Once preheated, the die is ready to be installed in the extrusion press.

Preheated aluminum billet pre-extrusion
Next, a cylindrical block of aluminum alloy, known as a billet, is cut from a larger batch of alloy material. This billet is then placed in an oven and heated to temperatures between 400 and 500 degrees celsius. The heating process makes the billet malleable enough for extrusion, but it does not reach a molten state.

Billet moved to the extrusion press
As soon as the billet is done preheating, it is mechanically moved to the extrusion press. Before loading it onto the press, a lubricant or release agent is applied to it. The release agent is also applied on the extrusion ram to prevent the ram and billet from sticking together.

Pushing the billet into the container
The malleable billet is then loaded into the extrusion press, where a hydraulic ram applies 15,000 tons of pressure. This immense force pushes the billet into the extrusion press’s chamber, causing the metal to expand and conform to the shape of the container walls.

Extruded solids
As the metal alloy fills the chamber, it is forced against the extrusion die. The sustained pressure confines the aluminum, allowing it to pass only through the openings of the die. The result is a completed pipe or tube that emerges from the die.

Running and quenching extrusions
Once the extrusion exits the die, a puller takes hold of it and guides it along the run-out table, synchronizing with its exit speed from the press. During this process, the pipe or tube is "quenched" by cooling it consistently, either with a fan positioned above the table or through a water bath.

Cut to table-length extrusions
After the extrusion reaches its full length on the table, it is cut using a heated saw to detach it from the extrusion process. Temperature is crucial throughout the entire procedure. Even though the extrusion is rapidly cooled after exiting the press, it remains warm and hasn't fully cooled down yet.

Cooling extrusions
Once cut, the extrusions are mechanically transferred from the run-out table to a cooling table. They remain there until they reach ambient temperature. After cooling, the next step involves stretching the pipes or tubes.

Stretcher transfer and stretched to alignment
Natural twisting in the pipes or tubes must be corrected. This is done by moving them to a stretcher, where each piece is clamped at both ends and stretched until it is straightened and meets the required specifications.

Cutting to length extrusions
Once the extrusion has been straightened and work-hardened, it is transferred to the saw table. Here, it is cut into predetermined lengths, typically ranging from 8 to 21 feet (2.4 to 6.4 meters). At this stage, the extrusion exhibits the t4 temper. Following the cutting process, the extrusions may be placed in an oven for aging to achieve the t6 or t5 temper.

Heat treating, finishing, and fabrication
After the extrusion process is complete, the pipes or tubes may undergo heat treatment to enhance their properties. Following this, various surface finishes are applied to boost their aesthetic appeal and provide better corrosion resistance. After heat treatment, piping is finished.