Hydraulic Vertical Duct Zipper

Machine Overview

The hydraulic vertical duct zipper is the closing station at the end of rectangular duct fabrication. Your lock former or folding machine produces the longitudinal lock; the section then stands on end against the machine's vertical column, the lock is engaged at the start of the run, and hydraulic force carries the seam closed along its full length. Nothing is hammered, so the finished joint is pressed flat and even from one end to the other.

Hydraulic closing changes what the operator does. Instead of walking a hand zipper or a mallet down the seam, they position the section, start the pass and steady the panel while the seam runs closed. The pass is quick and the machine runs quietly, which matters in a shop where several stations work in the same bay and where the operator stands close to the duct for most of the shift.

A flat, fully closed seam is also a functional seam. When the lock sits tight against the duct face, less air escapes at the joint, sealing and taping go on faster, and the duct keeps its shape better through handling and installation.

The station covers vertical seam joining for galvanized and stainless steel air ducts. Galvanized covers the bulk of HVAC work; stainless is what commercial kitchen exhaust, cleanroom supply and other moisture- or hygiene-sensitive systems are built from, and it is harder to close neatly by hand because it work-hardens and marks easily. Keeping both materials on one machine means stainless jobs stay on the same workflow instead of moving to a bench.

This is a closing machine, not a joining machine. It finishes the lock that already runs along one edge of a formed rectangular section; splicing two flat sheets edge to edge, welding a straight seam or fitting corner codes are different operations handled by different equipment. It is a standalone station, so it can be dropped into an existing duct line without rebuilding the line around it.

Key Features

• Hydraulic closing instead of hammer work — the seam is pressed closed by the machine rather than peened down by hand, so the lock is uniform from the first centimetre to the last and output no longer depends on how long an operator can keep swinging.
• A tight, flat joint — the closed lock sits against the duct face instead of standing proud, which cuts leakage at the seam and leaves a flat line for sealant, tape or paint.
• Quiet through the whole pass — hydraulic action replaces repeated mallet impact, so the station adds very little noise to a shop already running shears, folders and lock formers.
• Galvanized and stainless on one machine — the same closing station takes standard galvanized HVAC duct and the lighter stainless used for kitchen exhaust, cleanroom and hygiene-sensitive systems, so vertical seam joining for galvanized and stainless steel air ducts does not need a second station.
• A working length that covers standard modules — sections built to the module sizes most rectangular duct layouts use close in a single pass, without resetting the machine or turning the duct end for end.
• A compact floor footprint — the duct stands on end against the column instead of being fed flat across a bench, so the machine occupies a small area and leaves the aisle clear for moving sections.
• Controls at the operator's height — the panel with its display sits beside the closing column, so settings can be checked while the operator is still steadying the duct.

Specifications

Seam Closing Workflow

1. Form and fold the section first. The longitudinal lock has to exist before the section reaches the closing station; it comes off your lock former or folding machine with both edges folded to the profile the duct specification calls for.
2. Inspect the lock before closing. Run a hand along the seam, clear burrs and swarf, and check that the folded edges are engaged over the full length — a lock that starts crooked closes crooked.
3. Stand the section against the column. Position the duct on end with the seam in line with the closing column, and support the panel so it stays vertical while the pass runs.
4. Engage the start of the seam by hand. Square the lock at the entry point and feed the first part of the seam manually; once the machine has hold of it, the hydraulic action carries the seam forward.
5. Guide the duct through the pass. Keep light, even control of the panel, keep hands and sleeves clear of the closing line, and on stainless guide rather than drag so the surface stays unmarked.
6. Inspect what comes out. Check that the lock is closed tight and flat along the full length, and correct any open spot before the section goes on to flanging, corner assembly or insulation.
7. Re-check when you change material. Moving between galvanized and stainless, or dropping to a lighter gauge, changes how the seam behaves — close a scrap piece of the new material first and adjust before running production.

Duct Size & Material Fit

• Measure the finished section, not the flat blank — the working length applies to the duct section you stand at the machine, so check the assembled length of the section rather than the developed sheet size.
• Standard modules close in one pass — rectangular duct is normally built in short modules for handling, and the machine's working range covers that common band; longer runs are closed module by module before the sections are jointed together.
• Two materials, two behaviours — vertical seam joining for galvanized and stainless steel air ducts runs through the same closing station, but the metals are not equal to work: galvanized takes the full thickness band, while stainless is held to a lighter maximum and needs a cleaner, burr-free lock because it work-hardens and marks easily.
• Lighter gauges need control, not force — thin sheet distorts if the panel is pushed through, so let the machine close the seam and keep the duct square in the column instead of forcing it.
• Vertical handling keeps tall panels square — a tall section standing against the column is easier to control than a panel fed flat across a bench, and a second pair of hands makes full-size sections comfortable to position.
• Leave room to handle the duct — the machine itself is compact, but plan clear floor in front of the column for standing a full section upright and swinging it into position; that handling space is what makes the station comfortable to run.

Application Scenarios

Vertical seam joining for galvanized and stainless steel air ducts is a shop-floor operation, so the closing station earns its place wherever rectangular sections are made rather than bought in.

In a general HVAC duct shop the machine sits at the end of the line, after the lock former or folding machine and before flanging and corner assembly. Galvanized sections for offices, hotels, schools and commercial premises pass through it all day, and an evenly closed seam means the installer is not chasing leaks after the duct is up.

Commercial kitchen exhaust is the stainless case. Kitchen duct is built from stainless for grease and moisture resistance, the sections are often visible in plant areas, and the seam has to close without stretching or scuffing the surface — a hydraulic pass marks far less than hammer work.

Cleanroom, laboratory and hospital ventilation puts the emphasis on tightness. A seam that is fully closed along its length gives the sealing stage a flat, predictable surface, which matters when the system is specified to hold pressure and to be cleaned down.

Exposed ductwork — plant rooms, atrium runs, commercial ceiling voids — is judged on appearance. The pressed seam reads as a straight, deliberate line rather than a row of hammer marks, and it holds that line after transport and lifting.

Prefabrication shops supplying installation contractors work differently: they build standard modules, close the seams in the shop and ship sections ready to bolt together. Closing at the bench keeps the joint under control and takes the operation off the site, where access and noise are usually worse.

Industrial ventilation and dust extraction ducting in heavier galvanized sheet passes through the same station, as long as the gauge stays inside the machine's range; thicker material simply calls for a slower, more careful pass.

Ordering & Delivery

1. Send the work you need to close. Material mix, thickness range, section lengths and any drawing you already have — that is what the machine configuration is checked against.
2. Confirm the supply at your wall. Voltage, phase and frequency, plus where the machine will sit in the workshop, so the unit is built for your site rather than adapted afterwards.
3. Fix the configuration before production. As a hydraulic duct seam closer manufacturer we build each unit to the order, so the working length, control arrangement and the documentation you need are settled at that stage.
4. Agree commercial terms with your sales contact. Price, packing, shipping method, lead time and payment terms are confirmed in the quotation rather than assumed from a product listing.
5. Plan unloading and role. The machine arrives as a floor-standing unit, so have lifting equipment and a level position ready before it lands, and tell us in advance about stairs, narrow doorways or restricted access.
6. Arrange commissioning and operator training. Ask your sales contact about installation support, training for the people who will run the machine, and the spare parts worth keeping on the shelf so a small fault does not stop the line.

Maintenance & Spare Parts

• Keep the closing line and the vertical guide wiped down and free of metal dust at every shift change. Stainless runs leave fine abrasive swarf behind, and that swarf will mark the next galvanized panel if it is not cleared.
• Check the hydraulic oil level and walk the hoses and fittings before the first production pass. A weeping fitting or a low reservoir usually shows up first as a soft, uneven close rather than a sudden failure.
• Inspect the entry guide and the closing line for burrs and slivers. A single raised burr transfers to every seam that follows, so remove it with a fine file and re-check the lock on a scrap piece before running production.
• Ask us for the wear-part list for your HL-1500 and agree which items to keep on the shelf. The parts that stop a line tend to sit in the hydraulic circuit or at the seam entry, and holding them locally avoids waiting on an international shipment.
• Order spares by model and order code — HL-1500, order code 3039 — and send a photo of the old part where the number is not legible. That is the quickest way to get the correct replacement rather than a near match.
• Keep a simple maintenance log: oil top-ups, leaks found, any seam that closed unevenly, and the material and gauge running at the time. A repeat soft pass then supports the hydraulic system or a worn guide instead of being blamed on the operator.
• If the machine will sit idle for a long period, protect the column and closing line from rust, leave the hydraulic unit clean and covered, and run a test piece on scrap before the first production batch.
• Agree one stop condition with the operators: a change in the sound of the pass, a seam that will not close flat, or any visible leak means stop and check. Running to the end of a batch with a developing fault is what turns a small repair into a full rework.

Scale & Supply Capability

Tianjin Coorig Technology Co., Ltd. has been building sheet metal and MEP prefabrication equipment since 2004, with a team of around 200 people working from our own factory in Tianjin, China. In more than 20 years we have supplied buyers in over 35 countries — processing plants, mechanical installation contractors and agents — and we look after export, documentation and shipping as a one-stop service. A database of 3,000+ qualified suppliers, in-house quality control and our automated manufacturing systems keep build quality and delivery predictable. Reference work includes the Beijing Olympic Games, Egypt CBD, Guangzhou Baiyun Airport and BYD's European Center.

FAQ