Volume Control Dampers
PRD Series
Standard Model: PRD
Frame: Galvanized Steel Sheet
Blade: Aluminium Sheet
Blade Operation: Parallel
COSMOS Gravity Dampers have been specifically designed for use in Air-conditioning and Ventilation system, these dampers are air operated and are used for air intake and exhaust, and are also used for pressure relief. Gravity Dampers can either be operated by gravity (where pressure or velocity opens and closes the damper) or be motorized to open and close when required. Backdraft dampers are designed for applications where air should only flow in one direction.
Product Description
COSMOS Gravity Dampers have been specifically designed for use in Air-conditioning and Ventilation system, these dampers are air operated and are used for air intake and exhaust, and are also used for pressure relief. Gravity Dampers can either be operated by gravity (where pressure or velocity opens and closes the damper) or be motorized to open and close when required. Backdraft dampers are designed for applications where air should only flow in one direction. These dampers always start in the fully closed position. Once air flows in the intended direction, it pushes the blades of the damper into the open position.
As soon as airflow stops, the blades of the damper immediately fall to the closed position. If air flows in the opposite or wrong direction, then the blades will stay closed. This design ensures that air only goes in one direction and that airflow will not pass back through the other way. These dampers are composed of a set of horizontally mounted blades, they are normally closed and are free to rotate about the horizontal axis. The blades are manufactured from light weight aluminum sheets. Frame is manufactured from high quality aluminum as well as from galvanized steel.
Pressure Relief Damper
Pressure relief dampers are backdraft air dampers with an adjustable start-open pressure by manually adjusting the weight or the position of weights on each counter weight arm. This provides the capability of maintaining a relative constant pressure at various air flows. The damper closes when there is a decrease in differential pressure. This damper is generally used as a safety or controlling device.
Pressure relief dampers are used for the protection of internal spaces from differential pressures in excess of set maximum levels When the set maximum differential pressure is exceeded, the blades automatically open to relieve the excess pressure
Damper selection begins by determine the damper construction required based on system velocity and static pressure. While selecting the correct damper for our application, we need to know following
● System velocity and back pressure requirements.
● Mounting orientation and airflow direction.
● Mounting configuration (Inserted into duct / opening or flange mount / Duct mounted)
● Damper operation ( gravity or motorized )
● Start-open pressure
● Adjustable counterbalance weights are a more precise means of reducing the pressure that is required to open the damper.
Operating Principle
Pressure-relief damper will allow one-way pressure relief in the ductwork. This feature is based on imbalanced blades. When the pressure in the duct rises above selected value (from 5Pa to 50 Pa, up to 250 Pa optionally) the damper blades open to allow pressure relief. The minimum opening force can be adjusted with weights. When the pressure in the ductwork drops below minimum opening force required, the blades close and seal the duct.
Features
● The casing frame is fully sealed robust and rigid assembly formed out of best quality aluminum sheets / galvanized sheet steel of 1.2 mm thickness.
● Fully sealed low leakage blades are formed out of high quality light weight aluminum sheets of 1.0 mm thickness.
● The bearings are made of PVC / Nylon to give smooth and rattlefree operation.
● The blades are fitted with galvanized steel connecting spindle to main casing / frame for rigid and strong construction for rattlefree and smooth operation due to variable air pressure.
● A galvanized / aluminum angle is fitted internally to main frame to avoid over movement of blades.