Round Manual Air Regulating Damper

A round galvanized steel manual air regulating damper (AGRJ-R Series) is a precision-engineered HVAC component designed for the manual balancing, adjustment, and fine-tuning of volumetric airflow within circular duct networks. Equipped with a convenient manual handle adjustment lever, this regulating valve allows mechanical contractors to efficiently stabilize air balance, optimize heating or cooling distribution throughout the building layout, and prevent unwanted drafts. The defining characteristics of this series include its robust unsealed regulating blade configuration, engineered specifically for accurate volume throttling without any risk of blade stickiness or degradation under heavy continuous service cycles.

The structural casing and internal butterfly regulating disc are manufactured on high-speed automated lines from industrial-grade structural galvanized sheet steel, grade DX51D, carrying a dense protective hot-dip zinc coating mass of Z275 (275 g/m²). To ensure absolute geometric stability and prevent casing warping under constant network static pressure, the longitudinal body seam is fused via continuous automated linear seam welding. The regulating handle assembly is equipped with an integrated locking screw mechanism to firmly secure the balancing blade in the desired angle position.

Key Benefits of the Manual Air Regulating Damper

• Safe volume throttling and fan equipment protection: Designed with an unsealed Class 0 blade leakage profile, the metal disc preserves a calculated structural clearance when driven to the maximum closed position. This prevents dangerous static pressure buildups inside the air track, protects fan motors from thermal overload, and maintains a necessary baseline ventilation exchange rate.
• Elevated manual handle platform for insulation wrapping: The manual adjustment locking lever is raised on a rigid 50 mm metal standoff frame. This intentional clearance ensures insulation crews can easily apply external mineral wool blankets or foil cladding jackets around the duct line without blocking access or obstructing manual handle operation.
• Airtight casing design for lower pressure losses: The automated linear seam-welded steel casing meets rigid European Class C tightness standards (ATC 3 rating). This completely prevents unwanted air leakage through the body shell, maintaining the project's design pressure and optimizing fan power consumption.
• Rapid inline assembly with safe handling technology (up to D-400): Sized with a calibrated male connection profile, the ports slide effortlessly inside standard straight round ducts. Pre-rolled mechanical stop beads precisely restrict the insertion depth to prevent axial misalignment, while the collar rims feature machine-rolled SAFE technology to reinforce the ports and protect installers from hand cuts.
• Comprehensive size spectrum for any project scale: The manufacturing dimension matrix accommodates nominal duct cross-sections from 100 mm up to 1000 mm. This extensive range allows mechanical engineering teams to implement identical manual balancing nodes across small commercial zones and heavy industrial facilities.

Technical Specifications and Dimensional Data

The linear dimensions, diameter calibrations, and engineering construction tolerances of the AGRJ-R series fully comply with European standard EN 1506:2007 for circular sheet metal air ducts and fittings. The unit is shipped complete with a lockable manual control lever.

• Casing Airtightness Profile: Fully compliant with Class C / ATC 3 requirements
• Blade Leakage Profile: Unsealed regulating layout, Class 0 airtightness rating
• Base Material Profile: Structural galvanized sheet steel DX51D (Z275 passivation coating)
• Optional Materials: Available in stainless steel configurations (AISI 304 or AISI 316) upon request
• Control System Type: Manual adjusting control handle with integrated lock screw
• Connection Configuration: Double male ports calibrated for inline sliding inside duct paths

Recommended Assembly and Maintenance Guidelines

Mount the manual regulating damper within air track segments that offer adequate clearance for executing routine mechanical adjustments, technical inspection, and handle re-locking. The male-profile connection collars slide directly inside standard straight spiral-wound or longitudinal round ducts. Secure the overlapping connection perimeter mechanically using blind structural rivets or self-tapping sheet metal screws. External joint seams must be wrapped with high-adhesion aluminum duct tape to preserve the network design leakage category. If the installation requires joining the regulating damper directly to another molded configuration item (such as a bend or a tee piece), a female sleeve coupling connector must be used to bridge the male ports.