l Tütün s?z?nt?s?n? önler. Yaman s?zmas?n? engelleyerek yang?n merdiveninin duman alt?nda kalmas?na engeller. Bu sayede emniyetli tahliyeyi sa?lamlar.Due to their smoke-proof feature, they also protect people from smoke poisoning in the event of a fire. These doors, also known as emergency exit doors,  of the fire department  fire  occupies a