Abstract: An angularly shaped inflatable bladder assembly adaptable to use as a damper or shut-off means for control of fluid flow in fluid flow systems and more specifically for control of air flow in air conditioning systems. The angularly shaped bladder is formed of an assembly of fluid impermeable polymer sheet materials edge sealed. The bladder is bent to a desired angular form less than 180 degrees and at least one layer being flexible fluid conformable material without shape memory so that it responds to inflating fluid such as air pumped between the layers through a connection to the bladder. One or two inflatable pockets are provided upon bending the assembly along a line between two opposite edges of the bladder. Upon inflation the single or two pockets enlarge and push the opposite sides of the assembly further apart whereby the angle between the two becomes wider, or upon deflation the opposite sides are drawn together to narrow the angle.