1. Installed on the pipeline of the mechanical smoke exhaust system, it is normally open. When the smoke temperature in the exhaust pipe reaches 280 °C in the fire, it will be closed, and the smoke leakage and fire integrity requirements will be met within a certain period of time. Smoke and fire resistance.

2. 280 °C normally open, WSDc-K, (W) temperature sensor control automatically shut down, (S) manual open, (Dc) electromagnet control off, (F) air volume adjustment function, (K) valve closed or opened Valve position signal feedback function.