Steel Fire Proof Doors ;and frames play a critical role in keeping people safe and minimizing property damage. Doors play a very important role in the fire resistance of a building; they allow people to evacuate safely from a building along with limiting the spread of fire and smoke to other areas. Fire doors must meet the requirements of the International Building Code and International Fire Code, as well as the NFPA 80 Standard for Fire Doors and Other Opening Protectives. Fire ratings range from 20 minutes to 3 hours. http://www.jiahuicorp.com/