The types of fire doors are mainly divided into wood fire doors and steel fire doors. They are divided into three grades: Grade A, Grade B and Grade C. The three grades are mainly the length of fire endurance time. Class A fireproof door, with fire endurance of 1.2; Class B fireproof door, with fire endurance of 0.9; Class C fireproof door, with fire endurance of 0.6.

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