
Greenheck has expanded its line of isolation dampers with the new HBT-321 rectangular bubble-tight damper that is rated to 20 in. wg (5 kPa). Each HBT-321 damper unit is factory-tested to ensure bubble-tight leakage performance per AMCA 500-D prior to shipping and also meets ASME AG-1, Class 0A requirements. The HBT-321 can withstand velocities up to 4,000 fpm and a temperature range from -40 to 250 °F. Available in sizes up to 48 in. x 42 in., the HBT-321 allows larger openings to be filled with one pre-engineered damper to provide zero leakage rather than a multi-section assembly that can add significant pressure drop to the system. In addition, HBT-321 dampers can be supplied with a wide range of factory-installed actuators including electric, pneumatic, or manual actuator options.
Heavy-duty model HBT-321 features a fully welded frame, full-length axles, a field-replaceable sweep-style blade seal mechanically fastened to the blade, and a flanged damper frame for easy mounting. Designed for isolation or decontamination applications where leakage is critical, Greenheck’s HBT-321 bubble-tight damper is ideal for clean rooms, chemical and treatment plants, data centers, medical facilities, microelectronic manufacturing, bag in bag out (BIBO) filtration, laboratories, and testing facilities.