Spring Loaded Backdraft Damper

Spring loaded backdraft damper is a circular spring-operated non-return damper designed for round HVAC duct and exhaust systems. Equipped with a reliable spring return mechanism, this round backdraft damper features faster closing speed and tighter sealing than gravity-type dampers, effectively preventing reverse airflow, air backflow and pressure loss. Suitable for all installation angles and positive-pressure ventilation environments, the compact circular design enables easy connection with various round ductwork and fan equipment. Made of durable anti-corrosion metal materials with complete standard sizes and OEM customization available, it is widely used for residential, commercial and industrial exhaust ventilation systems.

Product Description

The Spring Loaded Backdraft Damper is designed to prevent reverse airflow in round HVAC and ventilation duct systems. Unlike gravity-operated dampers, this model is equipped with an internal spring mechanism that allows the blade to close automatically and securely once airflow stops or reverses. This ensures reliable backdraft prevention regardless of whether the damper is installed horizontally or vertically.

Its spring-return structure provides faster closing action and improved sealing performance, making it particularly suitable for applications where stable non-return control is required, such as kitchen exhaust, industrial ventilation, and positive pressure duct systems. The compact round body allows easy connection with spiral ducts, flexible ducts, and circular ventilation pipelines.

Manufactured from galvanized steel with optional custom materials and thicknesses, the damper offers durability, corrosion resistance, and long service life in demanding ventilation environments.

Key Features

  • Spring-Loaded Closing Mechanism Internal spring ensures automatic blade closure when airflow stops
  • Reliable Backdraft PreventionEffectively blocks reverse airflow, outside air intrusion, and pressure loss
  • Suitable for Any Installation PositionCan be installed horizontally or vertically
  • Fast ResponseSpring return action offers quicker closure than gravity-operated types
  • Compact Round DesignEasy to connect with round ducts and ventilation pipes
  • Durable Metal ConstructionCommonly made from galvanized steel for corrosion resistance
  • Low MaintenanceSimple mechanical design without motorized components
  • Customizable SpecificationsMaterial, thickness, and dimensions can be customized

Applications

  • Kitchen exhaust systems
  • Commercial ventilation systems
  • Industrial air exhaust systems
  • Positive pressure duct systems
  • Bathroom and toilet exhaust
  • Inline fan outlets
  • HVAC round duct installations
  • Airflow non-return protection in vertical or horizontal ducts

Technical Specifications

Parameter Value / Option
Product Name Spring Loaded Backdraft Damper
Type Spring Return Non-return Damper
Shape Round / Circular
Material Galvanized Steel
Optional Material Aluminum / Stainless Steel
Diameter Range 76 mm – 600 mm
Height 150 mm / 200 mm / 250 mm
Thickness 0.8 mm – 1.2 mm
Blade Type Single blade with spring mechanism
Installation Horizontal / Vertical
Function Prevent reverse airflow
Application HVAC / Kitchen Exhaust / Industrial Ventilation
Customization Material, size, and thickness available
OEM / ODM Available

Size Range

Diameter (mm) Height (mm) Thickness (mm)
76 150 0.8
80 150 0.8
100 150 0.8
110 150 0.8
125 150 0.8
150 150 0.8
160 150 0.8
200 200 0.8
219 200 0.8
250 200 0.8
273 200 0.8
300 200 1
350 200 1
400 250 1
450 250 1.2
500 250 1.2

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