Mechanical lock seam ductwork
Standard HVAC Ductwork
Mechanically seamed rectangular G90 galvanized ductwork for standard HVAC air distribution, return, exhaust, and equipment connections.
- Best for rectangular HVAC duct systems where Pittsburgh lock seam construction and standard transverse connections are acceptable.
- Offered in 26 ga through 18 ga G90 galvanized steel; heavier gauges or continuous welded seams should move to welded galvanized duct.
- Confirm connection type, liner/insulation, seal class, access openings, and face-to-face dimensions before release.
MaterialG90 Galvanized Steel
Gauge range26 ga - 18 ga
ConstructionPittsburgh lock seam
Construction Standard
| Application | Rectangular galvanized ductwork and fittings for HVAC supply, return, exhaust, rooftop equipment connections, and standard air distribution systems. |
| Material | G90 galvanized sheet steel is standard unless another coating requirement is listed on the quote. |
| Gauge range | Lock seam galvanized duct is offered from 26 gauge through 18 gauge. Heavier gauges are typically quoted as welded galvanized duct. |
| Seam construction | Pittsburgh / mechanical lock seam construction. This is a formed duct product, not a fully welded duct system. |
| Straight sections | Produced in nominal duct sections and field-fit lengths as released. Connection style affects face-to-face dimensions and should be selected before fabrication. |
| Connection options | Raw ends with couplers, slip-and-drive, TDC / Ductmate, and angle rings are available as shown or quoted. |
| Insulation options | Fiberglass liner, rigid duct board insulation, and Armaflex options are available for acoustic or thermal protection when quoted. |
| Quality check | Duct sections and fittings receive visual inspection before release. Leak testing, pressure testing, or certified inspection are by others unless quoted. |
Build Quality
Made to specBuilt to released dimensions, gauge, liner, and connection details.
Built toughG90 galvanized duct formed for standard HVAC service.
Quality checkedDuct sections and fittings receive visual inspection.
Lock seamPittsburgh seam construction for rectangular ductwork.
Fabrication Capabilities
| Duct sections | Rectangular galvanized straight duct, field-fit pieces, risers, drops, and custom lengths. |
| Fittings | Rectangular galvanized elbows, radius bends, offsets, tapers, reducers, transitions, branches, and tees. |
| Connections | Raw ends with couplers, slip-and-drive, TDC / Ductmate, angle rings, equipment transitions, collars, curb adapters, and roof penetration fittings are available. |
| Field-fit work | Short sections, piece-marked runs, and coordinated connection faces. |
| Shop details | Tabs, brackets, companion flanges, angle frames, reinforcement, and special flange details when requested. |
| Release support | Built from released dimensions with connection type, liner requirements, seal class, access openings, and piece marks coordinated before fabrication. |
Liner & Insulation
Fiberglass linerAcoustic or thermal fiberglass liner is available in 1/2" through 2" thicknesses when specified.
Rigid duct boardRigid duct board insulation can be quoted where the project needs additional thermal or acoustic protection outside the normal liner scope.
ArmaflexArmaflex options are available when the project requires flexible closed-cell insulation details.
AttachmentLiner is installed with water-based adhesive and spot welded liner pins unless another attachment method is quoted.
Connection Options
Couplers
Raw endsRaw ends with couplers for screw assembly.
S & Drive
Slip-and-driveStandard rectangular duct connection for mechanical assembly.
TDC / Ductmate
Bolted sealBolted frame connections with gasket or butyl sealant when specified.
Angle rings
Custom patternAngle rings, frames, and bolt patterns to match the application.
Optional Accessories
LinerFiberglass liner, rigid duct board insulation, Armaflex, liner pins, adhesive, and exposed-edge details.
AccessAccess doors, cleanout openings, inspection panels, and drain fittings.
SealingGasket, butyl sealant, mastic, or seal class details where specified and quoted.
Custom detailsReinforcement, tabs, brackets, piece marks, angle rings, and special hardware.
Required for Quote / Release
- Gauge, duct size, quantity, connection type, and required nominal or field-fit lengths.
- Approved drawing, sketch, or verified field dimensions with airflow/orientation noted.
- Connection details: raw ends with couplers, slip-and-drive, TDC / Ductmate, angle rings, bolt patterns, or companion flange needs.
- Liner or insulation type, thickness, exposed edges, access needs, and any acoustic or thermal requirements.
- Piece marks, access openings, reinforcement, pressure class, seal class, and any testing requirements.
Not Included Unless Quoted
- Installation, hoisting, rigging, roofing, roof penetration work, or field sealing unless quoted.
- Engineering, permits, inspections, balancing, cleaning, field finish touch-up, or listed-system certification.
- Leak testing, pressure testing, fire wrap, fire-rated enclosure, gaskets, sealant, hardware, companion flanges, or rework from changed release dimensions unless quoted.
Scope & Responsibility
Code note: Galvanized lock seam duct systems may be governed by mechanical code, local code, project specifications, pressure class, liner requirements, material/coating requirements, and AHJ requirements. Empire fabricates duct and fittings to released dimensions and quoted scope; final system design, material selection, installation method, field sealing, insulation requirements, clearances, balancing, and acceptance remain the responsibility of others unless expressly included.
Ready to Quote?
Let's get your duct package moving.
Send drawings, sketches, photos, or field measurements. Empire is ready to go to work for you.
quotes@empiremetalproducts.com
602-424-9980