How to distinguish between class A fire resistant door and class B fire resistant door from appearance ? What are the differences between the two refractories? Thank you !
From the perspective of appearances, grade A is 70mm, B 50mm. Their materials are the same .
First, the materials are the same. But the thickness of grade A and grade B fire doors is different juding from their appearances. Grade A :50. Grade B:45. Added question: Do you refer to steel fire door?
It is difficult to distinguish from appearance. Their fire endurance are also different. The filling refractories of grade A and Grade B fire resistance steel doors are all perlite. The only difference lies in the filler compaction density.
