Product Description
The GI Non-Return Damper (NRD), also known as a Backdraft Damper, is designed to permit airflow in one direction while automatically preventing reverse airflow. It operates without external power, using gravity or spring-assisted blades that open under positive air pressure and close when airflow stops or reverses. It is widely used in HVAC, ventilation, exhaust, and industrial air handling systems.
Construction Details
| Parameter | Specification |
|---|---|
| Material | Galvanized Iron (GI) Sheet |
| Frame Material | GI Sheet, 1 mm to 1.2 mm thick |
| Blade Material | GI Sheet, 0.6 mm to 0.8 mm thick |
| Blade Type | Multi-Blade Gravity Operated |
| Frame Depth | 100 mm as standard |
| Flange | 25 mm / 35mm TDF flange |
| Bearings | Nylon / Brass Bush |
| Type | Duct mounted, Wall Mounted, Circular type |
| Blade Supports | Self oiling bushes with 6mm rods |
| Airflow Direction | One-Way Only |
| Fasteners | Zinc-Plated Steel |
| Finish | Pre-Galvanized Finish |
| Welded Joints | Welded joints are protected with aluminium spray paint |
| Seal | Gasket for air tightness |
| Mounting | Horizontal or Vertical (as per design) |