Model FSD - A and B are a multiblade fire and smoke damper with 3V style Blades. they are designed for closure of the HVAC duct opening in emergency Fire situations. they are certified to withstand fire conditions for 2 hours (when installed vertically) and for 4 hours (when installed horizontally) as per UL555 testing standards , tested & approved by CBRI Roorkee. Model FSD - A and B can be used with airflow in either direction.
(Click below on the 'Documentation' Tab to view/download the desired technical submittal)