Product Description

A round longitudinal seam duct is a ventilation system element made from sheet metal by forming and joining the edges with a longitudinal seam (lock-seam or welded). Unlike spiral-wound pipes, longitudinal seam ducts have a perfectly smooth outer and inner surface.

This design ensures minimal aerodynamic resistance and is often used in systems where aesthetic appearance is important (open ceilings), non-standard diameters are required, or special materials (e.g., painted steel or aluminum) need to be used.

Key Features and Advantages

• Any Diameters: Production technology allows manufacturing ducts of both small and very large diameters (over 1250 mm) that cannot be produced by spiral winding.
• Smooth Surface: The absence of an external spiral seam makes the duct more aesthetically pleasing for design solutions, while the smooth inner surface reduces dust accumulation.
• Wide Range of Materials: We produce straight seam pipes not only from galvanized steel but also from stainless steel (AISI 304/316), aluminum, and polymer-coated steel (PE) in various colors.
• High Strength: The cylindrical geometry provides natural rigidity, allowing the use of metal with a thickness from 0.5 mm without loss of pressure resistance (according to EN 12237 standard).

Technical Specifications and Materials

Longitudinal seam ducts are manufactured on custom order. The standard element length is 1250 mm (determined by sheet width), but joining into longer sections is possible.

* Metal thickness is selected based on diameter and pressure requirements.

Available Materials:

• Galvanized Steel (Zn 275): Standard solution for general ventilation. Service life up to 25 years.
• PE Coated Steel (Poliesters): Galvanized steel with polymer coating (various RAL colors). Excellent corrosion protection and aesthetic appearance. Service life up to 50 years.
• Stainless Steel (AISI 304 / 316L): For food, chemical industries, and medical facilities. Highest hygiene and resistance to aggressive environments.
• Aluminum: For systems where low structural weight is critical or spark safety is required.

Application and Installation

• Installation: Ducts are connected to each other using nipples (for small and medium diameters) or flanges (for large diameters).
• Airtightness: To ensure airtightness class "B" or "C", joints must be sealed with sealant or reinforced aluminum tape.
• Areas of Application: From residential homes and offices (exposed installation) to industrial halls, swimming pools, and laboratories (in stainless steel execution).

Availability and Ordering

• Availability: Longitudinal seam ducts are manufactured on custom order.
• Capabilities: We can manufacture a pipe of any diameter, thickness, and metal (Galvanized, Stainless, Aluminum, RAL) upon your request.