Large layered fire screen sliding door - with bent edge sheet metal outer skins welded together and to frame

摘要

The large fire-protective door is in the form of a sliding door with sheet metal skin on both exterior surfaces and intervening panels of fire-resistant material, and a partially or wholly enclosing frame of angle sections connected by projecting stop or guide corner pieces. The sheet mtal membrane on one side, in the form of a shell (4) with bent-over edges (5), is edge-welded to the membrane (1) on the other side, the frame sections being also welded to them both. All the weld seams joining part of one side to part of the other are in the form of interrupted seams, with contact between the joined metal parts prevented at the joints where breaks in the seams occur.