They permit airflow to go in a single direction and to stop it in the other route. These are manufactured from corrosion resistant extruded aluminum. (2.0) equivalent laminated blade that is certainly double bolted to axles for favourable relationship. The 1290S smoke damper is designed and tested to provide premium https://dampers-for-industrial-se81223.theblogfairy.com/36102008/about-dampers-for-industrial-sector