53CRVD Type CR 3-Hour Dynamic Fire Damper (Round)

The 53CRVD is UL/ULC certified for use as a 3-hour dynamic fire damper in HVAC systems.

The 53CRVD is designed for installation in vertical fire-rated wall and floor assemblies using round ductwork in systems where fans are not shut down on fire alarm activation. Unlike static fire dampers, dynamic fire dampers are tested and rated to close reliably against live airflow, making them the required choice for systems that maintain fan operation during a fire event. The 3-hour fire rating makes it suitable for fire separations requiring a higher level of protection than the 1-1/2 hour 51-series dampers, including fire walls and high fire resistance rated assemblies up to 4 hours. The Type CR configuration accommodates round duct geometry while keeping the blades outside of the airflow path during normal operation. The interlocking curtain blade closes under spring tension when the fusible link releases.