Copper plumbing pipe is made through a process involving melting, casting, and shaping the copper into tubes.
Here's a breakdown of the steps:
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Melting: Copper ore is heated to a high temperature in a furnace to melt it and separate impurities. This process removes unwanted elements and refines the copper.
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Deoxidization: After melting, the copper undergoes deoxidization. This process removes oxygen, preventing the formation of flaws or weaknesses in the finished pipe.
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Casting: The molten copper is then cast into a cylindrical mold. This creates a solid copper cylinder, often referred to as a billet.
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Extrusion or Piercing: This is where the hollow shape of the pipe is created. There are two main methods:
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Extrusion: The copper billet is forced through a die (a shaped opening) while hot. A mandrel (a central shaping tool) is positioned inside the die to create the hollow center. This method is commonly used for smaller diameter pipes.
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Piercing: A rotating tool is forced into the center of a heated copper billet, creating a hole through the length of the cylinder. The resulting hollow is then expanded and shaped to the desired dimensions. This method is often used for larger diameter pipes.
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Drawing (Cold Drawing): The newly formed tube is then passed through a series of progressively smaller dies in a process called drawing (usually cold drawing). This reduces the diameter and wall thickness of the pipe, bringing it to the final dimensions and improving its strength and surface finish.
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Annealing (Optional): Depending on the desired temper (hardness or flexibility) of the pipe, it may be annealed. Annealing involves heating the copper to a specific temperature and then allowing it to cool slowly. This softens the copper, making it more ductile and easier to bend. Type L and K copper, commonly used for water supply lines, are often annealed to allow for bending. Type M copper is typically not annealed.
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Quality Control: Throughout the manufacturing process, the copper pipe undergoes rigorous quality control checks to ensure it meets industry standards for dimensions, strength, and purity.
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Marking and Packaging: Finally, the copper pipe is marked with relevant information, such as the type, size, and manufacturer, and then packaged for distribution.
