For blast resistant shelters that are concerned with leakage of NBC agents in military applications, or toxic chemicals in industrial applications, the sufficient protection to the HVAC duct systems including essential building openings such as air intake and exhaust openings, and the shut-off air-tight dampers, is critical to the safety of those stationed personnels inside the shelters. Blast valves or blast dampers play a key role in blast protection by minimizing the blast pressure loaded on openings of HVAC duct systems to the very low level. For example, FUCARE FC-RBV-11 high-performance blast valves, featured with tiny blades for fast closing, are capable of mitigating blast pressure of more than 13 bar peak pressure by long blast duration to passing through peak pressure of only 0.4 bar peak pressure by duration of only 3.5 ms. Nevertheless, there is minimum pressure passing through the blast valves and blast dampers given the fact the blast waves usually propagate at high speed of around 360m/s, so even high-performance blast valves like FC-RBV-11, are not able to shut off 100% blast pressure.
For industrial applications in which the blast pressure is normally less than 1 bar, the risk of the minimum passing through pressure from blast valves or blast dampers might be ignored. For military applications, however, the expected blast pressure by high explosives is normally set to 7 bar (100 psi) or more, so the passing through pressure does present tough challenge to the air-tight dampers. The commercial or regular air-tight dampers are normally designed for working pressure of 0.02 bar so their protection performance might be compromised significantly under the high passing through pressure from openings under blasts.
FUCARE’s FC-RLD-HP/LP heavy-duty bubble-tight dampers are designed to work under pressure up to 1 bar which could perfectly address the concern of high pressure in duct. FC-RLD-HP/LP product line has been rated to bubble-tight (Also called Zero-leakage) by AMCA 500D-18 at pressure up to 1 bar and rated to class 1 by nuclear powerplants standard, KTA 3601. Thus, this product line would be able to perfectly work with high-performance blast valves and blast dampers to provide reliable protection against threats from blast, nuclear, biological and chemical agents.
For more product information, please contact FUCARE distributors or representatives.