NIBCO Copper Manufacturing—Polished to Perfection

At NIBCO, copper is one of the four essential materials that create the foundation of products used in the plumbing, HVAC, industrial, irrigation and fire protection industries. The copper fittings and valves that NIBCO produces are all created through a copper manufacturing process; a detailed transformation that takes mined ore and turns it into a high-performance material.

Through advanced metallurgy, NIBCO uses a seven-step manufacturing process to ensure that its copper is “Polished to Perfection.” In this post, we will walk you through a detailed outline of how NIBCO’s copper products are created.

Copper is Melted  

The copper manufacturing process starts out using either an upcast or downcast furnace, both of which create copper rod and wire. These two furnaces are distinguished by the direction in which molten copper is drawn during the casting process.

The upcast furnace uses 99.9 percent pure copper cathode sheets; the molten copper is drawn upward into a cooled die where it is solidified. After loading the sheets into the melting furnace, they are heated to 2,200 degrees Fahrenheit. On the other hand, when using a downcast furnace, offal material—copper scrap—is drawn downward and solidified in a mold. During this process, the offal material is also heated to 2,200 degrees Fahrenheit as part of the pyrometallurgical refining of copper.

Cast Into Rod  

After the copper is melted in the upcast or downcast furnace, it is transferred to a cast. However, the size of the rod that is cast and produced is dependent on the furnace type. With an upcast furnace, the rod size produced is ¾-inch and 1-inch. The downcast furnace produces a much larger rod that is 6 inches in diameter.

Formed Into Coils and Billets   

After the upcast rod is produced, it needs to be sized to the proper dimension. The solid copper rod is coiled, allowing for ease when handling the material, and when put through a drawing operation, reduces the outside diameter to between 0.550 – 0.880 centimeters.

The downcast rods are cut into billets after production. Passing through two rollers, the solid rod with a diameter of 6 inches is straightened. After the rod is straightened, a cut-off saw is used to cut the rod into lengths of 7 inches through 10 inches.

Made Into Tube  

Using a piercing press, a hole is punched on each side of the downcast billet. The holes punched into the side of the downcast billet are sized intentionally, representing the inside dimension of the tube that will be created. The pierced billet is placed on an extrusion press where a hydraulically driven ram forces the copper through a die, effectively creating a piece of tube. The tube is then reduced further by pulling it through a series of smaller dies, drawing it down to various diameters.

Cut and Annealed  

 The tubes created from downcast billets are then cut into various lengths based on their future purpose. Then, the copper is annealed by heating each blank to 1,400 degrees Fahrenheit; annealing the copper makes it softer and more pliable, allowing for it to bend without breaking.  

Formed Into Fittings 

When forming copper tubes into fittings, blanks are inserted in either a punch press, tee press or a bender.

A tee press is used in the hydroform process, where the blank is formed in the tee press to create the correct shape. After this, the outlet is opened at the end through a clipping operation. The fitting is then expanded during a process called the sizing operation for the acceptance of the water tube.

When using a punch press or a bender, mechanical force and proper tooling dimensions create the fitting’s geometry. The bending process involves a bending machine applying pressure to bend the tube around a die; the precise tool ensures specific measurements such as bend radius and angle. Contrastingly, when a blank is inserted into a punch press the press uses a high-speed ram to cut the material with extreme precision. Following the use of a bender or punch press the fitting is put through various end forming operations to produce the final fitting.

Final Steps 

The final step of the copper manufacturing process is called burnishing, which is the process of smoothing and polishing the surface of a copper fitting. The fitting is cleaned of all lubricants used during manufacturing and smoothed on the surface which enhances durability and appearance. After the fitting is smoothed and cleaned, an inhibitor is applied to prevent oxidation, effectively ensuring the quality and longevity of the piece.

Finally, the fittings are packaged and sent to NIBCO’s distribution center where they are shipped to customers!