They allow airflow to pass in one path and to avoid it in the other route. These are manufactured from corrosion resistant extruded aluminum. Do not promptly open up absolutely on achieving their start out-open up strain. HPR sequence dampers are flange mounted with counterbalance weights mounted externally for simple https://dampers-for-industrial-se02233.theideasblog.com/37568216/a-secret-weapon-for-dampers-for-industrial-sector