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Professional Service
Spiral Duct Fabrication
High-Performance Helical Round Systems
Diaz Sheet Metal specializes in the fabrication of helically formed spiral duct with high structural integrity. Our round spiral systems are the industry standard for commercial HVAC, offering superior airflow, significantly reduced leakage, and a professional exposed-aesthetic finish.
Our Services
Helical Integrity
Helically formed spiral lockseams provide extreme rigidity, allowing for lighter gauges without sacrificing pressure rating.
Surgical Precision
Fabricated based on approved shop drawings and CNC-plasma cut templates for 100% field-fit accuracy.
SMACNA Standards
All spiral ductwork is fabricated to meet or exceed SMACNA low, medium, and high-pressure class requirements.
Airflow Performance
Superior laminar flow characteristics reduce static pressure loss and operational energy costs.
Why Choose Diaz Sheet Metal?
Centerline-aligned concentric design for suspended systems
Available in diameters from 3" to 60" in various lengths
Multiple material options: Galvanized, Stainless Steel, and Aluminum
Significant reduction in air leakage (Class 3 leakage rated)
Professional exposed aesthetic for modern architectural designs
Reduced installation time compared to rectangular alternatives
Field Utility: Weight Estimator
Technical Spec Estimator
Estimate the total weight of your round duct section based on SMACNA standard gauges. Essential for calculating hanger loads and logistics.
Estimated Weight
0.0LBS
Includes:Seams & Flanges (+10%)
This is an engineering estimate based on standard galvanized steel densities. Actual weights may vary by finish.
Our Process
1
Technical Review
We analyze your blueprints and field dimensions to ensure perfect alignment.
2
Precision Fabrication
Computer-aided helical forming and CNC component cutting in our MD facility.
3
Quality Control
Rigid inspection of lockseams, connectors, and gauge thickness per project specs.
4
Project Delivery
Rapid turnaround and professional delivery to keep your mechanical schedule on track.
Frequently Asked Questions
Why choose spiral duct over rectangular duct?▼
Spiral duct is more aerodynamic, resulting in lower pressure drop and fan energy savings. It also has fewer joints, which means less potential for leakage and faster installation times on the job site.
What gauges and pressure classes do you support?▼
We typically fabricate in 26 GA to 18 GA depending on diameter. Our systems can be built to support low, medium, and high-pressure classes up to 10" w.g. as per SMACNA tables.
Can you provide specialized connectors?▼
Yes. We offer standard slip joints, gasketed E-Z flange systems, and companion angle rings for heavy-duty industrial or high-pressure applications.
How should spiral duct be supported?▼
Per SMACNA standards, we recommend support every 8–10 ft for diameters up to 18", and every 6 ft for larger sizes using strap hangers or cable systems like Gripple.
Ready to Get Started?
Contact us today for a free estimate on your spiral duct fabrication project.