Picture shown is of 10 inch bypass dampers, other sizes similar.  

If you need an additional weight, just let us know and we will ship you one at no additional charge.  

Durozone 8 (eight) inch inch round pressure relief (also called bypass or barometric relief damper, or dump damper) is used in zone control systems to bypass air from the supply side of the HVAC unit to the return side, in order to control high static pressure caused by closing off ducts with dampers, as part of a zone control system.    One of the oldest and most proven designs in the  damper business, the Durozone DDRD damper is an outstanding value and features an extra long arm and adjustable weight for enhanced control.  This Bypass damper uses no electricity.

  A 5 year Warranty is standard with this bypass damper.  Check our pictures:   blades riveted (not spot welded) with heavy duty construction throughout.  Compatible with virtually any  Zone control system needing a bypass damper. 

*Heavy duty galvanized metal can.

*Reinforcing beads on heavy duty galvanized can.

*Blade is riveted on, not cheap spot welded!

*service and support at 972 633 8104 during regular business hours. 

*low leakage gasket seals.

*Outstanding long time USA manufacturer with great reputation. 

From Damper Direct, where zoning is our only business! We offer the service, support, and technical resources to help you design or service your Zone Control System.

We handle all major brands including Durozone, Honeywell, EWC, Retrozone, Enerzone Systems Corp., Robertshaw, Invensys and more. If you dont see it on ebay, please ask and we can do a special Ebay auction for the part you need.