1. Installed at the end of each branch pipe (smoke inlet) of the mechanical smoke exhaust system, it is normally closed and meets the requirements of air leakage. When fire or need to exhaust smoke, it is manually and electrically opened to function as a smoke exhaust. A valve with a decorative opening or a decorative treatment is called a smoke outlet.

2. Normally closed, SDc-K, (S) manual off, (Dc) electromagnet control on, (K) valve position signal feedback function after valve is closed or opened.