Introduction: A workshop view of HVAC duct line modules shows how feeding, forming, punching, shearing, and closure stages connect on the floor.
If you walk into a sheet metal shop that fabricates rectangular duct, the production line is rarely just one machine. It is a sequence of modules arranged around one material flow. Coil comes in at one end, sheet moves through leveling, reinforcing, punching, square forming, and shearing, and a flat blank leaves at the other end. From there, separate lock forming or seam closing equipment turns that blank into a closed duct. Understanding where each module sits helps shop learners read a layout, plan material movement, and see why published machine length matters before equipment is placed.
The coil feeding end is the first place to look when reading a duct line layout. This is where the electric uncoiler, coil trays, and feeding device sit. On a line such as the COORIG Auto Duct Line 3, the uncoiler carries two 7000 kg trays, which means the starting module is a heavy material-handling zone that needs room for coil loading, coil changes, and a straight path into the feeding device. The feeding device then guides the strip into the main machine. If the coil sits too far off the line or forces the strip to turn before entering, the whole workshop flow becomes harder to manage. The feeding module sets the direction for everything downstream. Machine length becomes real at this point. The published Auto Duct Line 3 reference from COORIG Sheet Metal Machine Manufacturer lists 8200 mm and 9200 mm machine lengths, depending on configuration. That length runs along the material flow, so it tells a workshop learner how much linear floor space the main processing path occupies. Width also changes with the sheet size: a 1250 mm line and a 1500 mm line use different machine widths. The coil area, the operator position, and the discharge end sit around that published machine length. Exact site planning beyond those published dimensions depends on project engineering data, because real workshops have different columns, doors, power routes, and material routes.
Once the strip enters the main machine, the modules stop being separate boxes and become one continuous processing zone. Leveling, reinforcing, punching, square forming, and shearing are arranged in a fixed order inside that zone. This is why the main machine acts as the spine of the workshop layout. It connects the coil feeding end to the blank discharge end, and it determines where operators stand, where scrap falls, and where finished blanks leave the line. A learner who can picture this spine can walk through almost any rectangular duct shop and recognize which side is the material inlet, which side is the formed blank outlet, and where the next stage must connect.
Leveling and reinforcing sit before punching because punching needs a flat, stable sheet. Coil stock arrives with curvature and residual stress from winding. The leveling module works that material into a flatter strip so it can feed evenly. The reinforcing module then adds stiffening ribs or beads that help the sheet hold shape during later forming. When the sheet is leveled well, it feeds smoothly into the punching zone, and hole positions or notch locations line up as expected. When reinforcing matches the sheet, the formed duct keeps rigidity. In workshop flow terms, these modules are the preparation stage: they shape the sheet so the punching and forming stages can work with a predictable material.
Square forming and shearing come near the end of the main machine. Square forming creates the bends or fold lines that will later become the corners of a rectangular duct. Shearing then cuts the sheet to the required length, producing a flat blank. At this point the material has left continuous coil flow and entered batch handling of individual blanks. It is a prepared blank that carries the correct length, notches, holes, and fold lines for the chosen duct size. The discharge end of the line works best when it points toward the next operation, with clear space for transfer or temporary holding. Workshop layout has to treat this end as a transition point where continuous coil flow becomes individual blank handling.
After shearing, the material flow changes shape. A coil line moves a continuous strip, while the downstream stages handle separate blanks. That change matters for workshop layout because blanks need somewhere to go: an outfeed table, a transfer cart, a rack, or a buffer zone before lock forming or seam closing. Lock forming creates the mechanical joint that will hold the duct edges together, and seam closing finishes that joint. On many rectangular duct lines, these stages are separate machines or part of a higher line level. The Auto Duct Line 3 itself covers uncoiling through shearing, so the closure stage is where the shop connects one production line to the next. The connection is spatial as much as technical. A Pittsburgh lock former, a TDF flange former, a TDC notcher, or a seam closer may sit downstream of the shear, and the shear end works best when the first downstream machine sits close enough to keep blanks moving steadily while leaving room for operators to inspect and move them. Different duct connection styles also change what the downstream stage needs, so the blank discharge area should be planned around the dominant work in the shop. A compact layout keeps the shear end close to the first downstream machine while preserving a clear path for blanks and operators. The Auto Duct Line 3 runs at 9 kW and up to 15 m/min, with published machine lengths of 8200 mm and 9200 mm. Those figures help readers understand the footprint of the coil-to-blank stage before they look at how lock forming, flange forming, or seam closing will fit around it.
HVAC duct production line modules make more sense when you read them as a workshop flow rather than a list of machine names. The coil feeding module starts the path, the main machine carries leveling, reinforcing, punching, square forming, and shearing, and the discharge end hands off flat blanks to lock forming or seam closing equipment. Published machine length, coil tray size, and sheet width all shape how that flow sits on the floor. For a workshop learner, the useful habit is to trace material movement first, then place the modules around it. Product specifications can then be checked against the actual layout needs of the shop.
A：A typical rectangular duct line includes an uncoiling module with coil trays, a feeding device, a main machine with leveling, reinforcing, punching, square forming, and shearing sections, and a control system. Later stages such as lock forming, flange forming, and seam closing may be separate machines or part of a higher line level, depending on the shop setup.
A：Published machine lengths such as 8200 mm and 9200 mm define the main processing path along the material flow. That length affects where the coil feeding zone, operator positions, and discharge end can sit. Width also changes with 1250 mm or 1500 mm sheet capacity. Exact placement beyond published dimensions depends on the actual building and project engineering data.
A：After shearing, the line produces a flat blank with the correct length, notches, holes, and fold lines. That blank still needs lock forming or flange forming, and then seam closing or another joining step, before it becomes a closed rectangular duct. The shear discharge area should connect clearly to those downstream stages.
Provision and Use of Work Equipment Regulations 1998 (PUWER) - HSE
Commercial Buildings Integration | Department of Energy
