NonInsulated Non-return Damper

The non-return dampers are designed for ventilation ductwork systems which require air tightness class D according to EN 12237 requirements. These dampers feature a split flap closure and are designed as non-return dampers which allows a single air flow direction only. The damper closure has approximately air tightness class 2 as per EN 1751:2002, without full class compliance. Both closure flaps are made of light-weight aluminum sheet and hinged on a steel bar with springs which keep the flaps closed when there is no air flow. This damper is often installed upstream of an air intake or an air exhaust unit to prevent the air backflow. Standard dampers are made from galvanized steel sheet. Others are available on request.