Class a fire door
The fire door is what we now call the complete fire door, mainly within the stipulated time, able to meet fire resistance requirements for heat insulation and fire resistance integrity, fire resistance rating respectively, 0.5h (c), 1.0h (serie b), 1.5h (class a) and 2.0h, 3.0h.
Class b fire door
This door is part of the fire door, which fire doors fire resistance lower than the former, requirement of 0.5 hours, fire integrity levels respectively, 1.0h, 1.5h, 2.0h, 3.0h.
Class c fire door
This is the least secure of non fire door, the fire door fire insulation is not required, within the specified fire-resistance time of only meet the requirements of fire integrity, fire integrity levels respectively, 1.0h, 1.5h, 2.0h, 3.0h.