The FD-340 fire damper employs triple-V blades for point-of-origin control of fire in static and dynamic HVAC systems. The FD-340 is qualified to 4,000 ft/min (20.3 m/s) and 6 in.wg. (1.5 kPa) and may be installed in vertical walls or partitions with fire resistance ratings up to 4 hours.