the valve body is installed in the ventilation, air conditioning system back to the air duct, usually open state, fire when the flue gas temperature in the pipeline reaches 70℃ when closed, and in a certain time to meet the smoke leakage and fire integrity requirements, smoke isolation and fire resistance function of the valve.  

Type 11-62-E low-noise multi-wing centrifugal fan is a series of products derived from 11-62A. It is driven by belt and can adjust air volume and pressure, so that users can increase a variety of parameters to choose. the product has large air volume and low noise.