Round Ventilation Silencer 50mm

A round galvanized steel ventilation silencer with a 50 mm insulation thickness (also known as a circular duct attenuator) is a high-performance acoustic device engineered to suppress sound waves and aerodynamic vibrations within circular air duct networks. This inline sound attenuator is typically integrated directly downstream from supply air handling units, duct fans, or air conditioning equipment. It serves as a vital acoustic barrier in residential apartments, private houses, modern quiet office spaces, server rooms, and commercial plant zones where operating machinery generates a continuous background hum, effectively restoring a quiet and productive environment.

The external casing is manufactured on automated machinery from heavy-duty hot-dip galvanized sheet steel, grade DX51D, featuring a robust zinc coating mass of Z275 (275 g/m²). High-density, non-combustible basalt mineral wool is utilized as the internal sound-absorbing media. This premium rock wool insulation maintains its structural integrity under continuous high-velocity air streams, resists settling caused by system vibrations, and fully aligns with strict building fire safety regulations.

Key Benefits of the 50mm Round Silencer

• High sound attenuation across a broad frequency spectrum: When sound waves from the fan motor pass through the inner perforated liner, they enter the micro-porous matrix of the basalt mineral fiber core and dissipate entirely, neutralizing low-frequency hums and high-frequency whistles without increasing network static pressure.
• Double-layer protection against fiber erosion: Constructed with a solid outer protective shell and a fully perforated inner core sleeve. A specialized protective non-woven fabric barrier is lined between the mineral wool and the perforations, completely preventing the migration of glass or basalt micro-particles into the airstream to keep supply air perfectly clean and safe.
• Streamlined inline installation with male connection collars: Sized with a calibrated male connection profile, the silencer ports slide directly into straight circular ducts. Integrated mechanical stop beads precisely lock the insertion depth, preventing layout misalignment and allowing fast mechanical fixing with standard rivets or self-tapping screws.
• Factory-fitted double-lipped EPDM gaskets for perfect sealing: The connection collars feature pre-installed dual-blade rubber gaskets that compressed tightly against the inner pipe walls. This provides an immediate Airtightness Class D junction without requiring external mastic or sealing tape, saving labor and material costs.

Technical Specifications and Acoustic Performance

Linear dimensions, installation tolerances, and nominal port calibrations comply fully with European standards EN 1505:2000 and EN 1506:2007. The internal perforated sleeve leaves the net free area of the duct fully unobstructed, minimizing the total aerodynamic load on the fan equipment.

Standard Available Dimensions

Acoustic Attenuation Efficiency Data

The following performance indicators define the real sound suppression capability (Efficiency S, dB) across standard octave bands specifically for the 50 mm insulation thickness layer configuration, as derived from technical catalog test data (Image 5838ce.jpg):

Assembly and Application Guidelines

The acoustic attenuator must be installed directly into the straight run of the circular ventilation line, preferably immediately following the fan assembly unit or air handling module. The connection collars insert inside the adjoining ducts until they sit flush against the center stop bead. Secure the joint points mechanically using standard structural rivets or self-tapping sheet metal screws. If the design requires joining the silencer directly to another molded configuration element like a bend or a tee piece, a female sleeve coupling connector must be implemented to bridge the two male ports.