Fire door sealing requirements

China National Standard for the size of the gap of the fire rated steel doors between the gaps is clear:, the fan and the door frame of the metal fire door shall not be less than 10mm, the two sides of the gap between the door and the door frame should not be greater than 4mm. After the fire door is closed, the gap can not be too large, otherwise it is difficult to ensure the sealing performance of the fire door, it is difficult to reflect the fire and smoke spread under the conditions of fire.Therefore, the installation of the gap width of fire doors must be strictly controlled. According to the standard specification for installation, it can guarantee the effect of the fire rated wood doors in a certain extent, consumers must supervise in construction employment site, to prevent shoddy problem, so the fire door will not cause casualties in the fire.