Non Return Dampers
Non return or back draft damper which is used to prevent reverse flow. The criteria here is that the device shall be self-acting and not require an actuator, the resistance to forward flow shall be as low as possible.
Manufactured to withstand the reverse pressure and the reverse leakage of our Badger Damper non returns is very low. Badger has successfully developed the blade to offer sufficient strength to absorb the reverse pressure load whilst being low blade weight to minimize pressure loss under forward flow.
Badger damper offers a proven range of non-return dampers used in many industries. Supplied as circular or square / rectangular units. Designed to suit both horizontal and vertical flow. Our proven blade design features a robust box section leading which gives high strength coupled with light weight. The design has been honed to move the centre of gravity towards the pivot axis.
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Again, we place great stress on the design of our blades. This type of device relies on the flow of air to lift the blades and hold them open.
The force required has to come from somewhere and manifests itself as a pressure drop across the damper which has to be paid for in terms of power absorbed by the fan.
Our blade is effectively under-cambered like the wing section of a high performance glider. Thus, unlike the simple plate blade often employed, our blade lifts into position rather than being blasted open, with consequent lower pressure drop. The rounded leading edge enhances performance and ensures quiet operation.
As with all devices of this type, lowest possible blade weight is essential, dictating the use of light gauge material. The leading edge box on our design provides the stiffness and strength to resist the loads distributed over the blades in a reverse flow situation.
This type of damper is available in the same range of materials as our Louvre Dampers, and can also be designed for blade spans up to 2 metres, depending on maximum possible reverse pressure. With the addition of linkage and a tensioning spring, it can also be configured as a passive pressure control damper.
All units can be supplied in Mild Steel, Stainless Steel with finishes to suit everyone’s requirements.
