HBS-430 and HBS-431 blast dampers are designed to protect against blasts and instantaneous pressure changes. The heavy-duty, double-flanged, channel-frame-style dampers with double-thickness fabricated airfoil blades are qualified for pressures as high as 15 psi, covering many applications in Unified Facilities Criteria and General Services Administration codes and standards, including Charge Weight I at 82 ft. HBS-430 and HBS-431 are well-suited for government buildings and protection of ventilation systems.