How are Sheet Metal Ducts Made?

There are basically two types of ductwork. The first type, which is also the most frequently used, is rigid and often made of galvanized sheet metal. The other type is flexible and is usually constructed with plastic. This blog will take a deeper look at the former type and how exactly this ducting is constructed.

When metal ductwork is installed in a building, it is custom fitted so that it fits exactly into the dimensions in the floor, ceiling or wall. There is a number of ducting parts that are commonly built that are then assembled and modified at the build site. It is kind of like putting together a kid’s construction set. A variety of pieces are provided and then pieced together to make a functioning air flow system. The common ducting shapes include:

  • Straight round pipe
  • Straight oval pipe
  • Half sheet rectangular pipe
  • 90 degree adjustable elbow
  • X, Y and Z connector pieces

Machinery Does the Fabricating Job

Sheet metal, the raw material for rigid ducting, can be cut and shaped by hand, but this is a difficult task. Automated machines do the work of cutting, folding and grooving to create all the different components needed to assemble a new ducting network.

Rectangular metal ducts are built by putting two pieces of bent sheeting together. The flat pieces of metal are first cut to the desired size with a cutting machine or plasma cutter. Then, another machine folds the sharp edges inward. Thirdly, the sheet is shaped into an L or a tube. Most rectangular ducting is made to standard sizes, but the machines can be adjusted to create the ducting in custom sizes.

Round metal duct, also known as spiral pipes, are made with a different process. At the start of the process, the sheet metal is put into a machine that coils it. The machine fuses the edges together to make the pipe air-tight. The pipe is then passed to the next processing step where it is cut to the desired length.

The ductwork in your building is a critical component for the safe and healthy use of the facility. Give us a call today at 408-295-2182 to learn more about the ventilation services that we provide.