Circular Spiral Ducts for Ventilation Systems

Galvanized steel spiral circular ducts form the backbone of any reliable and high-performance supply or extract ventilation system. Unlike rectangular alternatives, the circular cross-section minimizes airflow resistance, ensuring quieter and more efficient system performance. For the end user, this translates directly into tangible savings: reduced system pressure losses allow fans to consume less power and operate without overload, significantly extending equipment lifespan.

These spiral-wound ducts are manufactured through the continuous interlocking winding of galvanized steel strip. The external spiral lock seam provides exceptional rigidity along the entire length of the tube. Starting from a diameter of 315 mm, the ducts feature factory-rolled stiffening corrugations that help them withstand operating pressure without deformation. The standard manufacturing length is 3000 mm, enabling rapid installation of long duct runs with a minimal number of joints.

Design Features & Benefits

Engineered geometry and standardized dimensions of our circular ventilation ducts simplify both system design and on-site installation:

• Precise Fitting Integration: Designed with a standard female connection profile, allowing standard duct fittings (bends, tees, reducers) to slide directly inside the tube without extra couplers, ensuring a snug and secure fit.
• Factory Stiffening Ribs: Ducts with diameters of 315 mm and above come with pre-rolled longitudinal corrugations. This reinforces the duct wall, preventing deflection and "panting" (oil-canning) caused by pressure fluctuations within the network.
• High Strength-to-Weight Ratio: Superior structural rigidity allows for optimized metal thickness. The ductwork does not overload the building’s load-bearing structures while remaining highly resistant to mechanical impacts and fan-induced vibrations.

Applications & Installation Guidelines

Galvanized steel ducts are versatile solutions suitable for residential buildings, modern offices, restaurants, shopping centers, and industrial facilities. Thanks to their clean circular aesthetic, they are also ideal for exposed installation in contemporary loft-style interiors.

To ensure the ventilation system operates flawlessly and maintains airtightness, we recommend following these basic installation practices:

• To connect two straight duct lengths together, use a matching male coupling (connector) of the appropriate diameter.
• Secure the ductwork to ceilings or walls using steel duct clamps equipped with rubber aging-resistant vibration dampeners — this drastically reduces the transmission of fan noise to the building structure.
• After assembly, seal all joints with self-adhesive aluminum tape to minimize the risk of air leakage and eliminate whistling or localized noise.

Technical Specifications & Quality Standards

We supply premium products engineered for decades of reliable service under diverse environmental conditions:

• Premium Raw Materials: Manufactured from DX51D grade galvanized steel with a consistent Z275 zinc coating (275 g/m²). This guarantees robust corrosion protection in environments with standard humidity levels.
• Calibrated Metal Thickness: Strictly monitored and ranging from 0.5 mm to 0.9 mm depending on the duct diameter, ensuring optimal geometric stability and structural integrity.
• Full Standardization: Strictly comply with the European standard EN 1506:2007