This type of damper is designed to control the volume air flow rate
by controlling the flow area by means of the a set of opposed blades.
This arrangement will give a free area of more than 94% when fully
open , and; less than 6% when fully closed.
This damper can be installed
on any type of Air grille as shown in Table G-1 by means of “S”
clip to ensure tight attachment and maximum flexibility. The Damper
is made pf extruded aluminum alloy heat treated to T6.