Although HVAC ductwork is a prominent feature in modern buildings, most people give little thought to how it's created. HVAC ducts are products of sheet metal fabrication processes. The four main processes involved in the fabrication of sheet metal HVAC are cutting, forming, assembling and finishing. Learn what each process entails below.
Sheet Metal Cutting
This is the process of separating or removing unneeded material from sheet metal by applying shearing forces on the metal. There are a variety of manually-operated and automated tools and machines used in cutting operations. These include hydraulic shears, electric power saws, laser cutters, water-jet cutters, CNC punching machines, press brakes, plasma cutters and many more.
Each sheet metal cutting method has unique pros and cons that should be reviewed before it can be used. The right cutting technique will depend on the specific requirements of each job. For example, punching is required where there's a need to create perforation in sheet metal.
Sheet Metal Forming
This is a process of sheet metal deformation in which force is applied to modify the geometry of sheet metal rather than removing or separating any material. The applied force gives the possibility to bend or stretch a piece of sheet metal to create a variety of complex shapes.
A variety of sheet metal forming processes exist. Some of the most common ones include:
- Bending
- Roll forming
- Stretch forming
- Spinning
- Drawing
- Stamping
The choice of the appropriate metal forming operation will depend on the requirements of a job. Choosing the wrong forming operation may result in a defective job. Some common types of defects found in sheet metal forming jobs include splits, wrinkles and springback.
Sheet Metal Assembling
After pieces of sheet metal have been cut and formed, they will need to be joined together to create a functional HVAC ductwork. Different methods of assembly can be used to achieve a complete fabrication. These include:
- Welding.
- Rivet assembly.
- Soldering assembly.
- Binding with adhesives.
- Binding with threaded fasteners.
- Mechanical assembly with hardware such as bolts, nuts and screws.
- Crimping, which is bending sheet metal in the form of a crimped seam.
A combination of joining and assembly techniques is typically used to achieve airtight HVAC ductwork fabrication.
Sheet Metal Finishing
Different types of metal materials are used for sheet metal HVAC fabrication. These include stainless steel, carbon steel, cold-rolled steel, aluminium, copper, brass and more. Within each type of metal, there are many finishing choices for protection, aesthetics or both.
When it comes to sheet metal HVAC fabrication, every aspect of the job must be done correctly in order to meet customer specifications. Talk to a sheet metal HVAC fabrication professional near you to discuss your project.
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