The difference between different grades of fire doors is not too obvious in appearance, and it is not easy to distinguish, but we, as engineering practitioners, need to learn to judge.



There are three methods commonly used to distinguish the grade of fire doors on site.



First, check the fire door acceptance data



Check the product inspection report, certificate, production license, fire door electronic ID card and other fire acceptance data when the fire door leaves the factory, which indicates the material and fire door grade.



Second, check the fire door nameplate



Check the manufacturer's nameplate on the fire door frame, which indicates the name, address and contact information of the manufacturer, and also marks the material and fire rating.



Three, measurement of fire door specifications



In order to further confirm the grade of the fire door, it can also be verified by measuring the specifications of the fire door. The thickness of the steel grade A door frame is generally 12cm, and the thickness of the door fan is 5cm; The thickness of the steel B grade door frame is generally 11cm, and the thickness of the door fan is 4.5cm; The thickness of the steel grade C door frame is generally 10cm, and the thickness of the door fan is 4.2cm; The thickness of the wooden class-A door frame is generally 10cm, and the thickness of the door fan is 4.5-5.5cm; The thickness of the wooden B grade door frame is 10cm, and the thickness of the door fan is 4-5cm; The thickness of the wooden class C door frame is also 10cm, and the thickness of the door fan is 4cm.