Lap-joint flange

A lap-joint flange is a loose backing ring that slips over the pipe and transfers bolt load to a lapped end or stub end. The flange ring itself is not the butt-welded process end; the companion end provides the mating surface, while the ring can rotate for bolt-hole alignment. It is therefore distinct from long- and short-pattern butt-weld stub ends, and neither companion component is assumed to be included with the other. Selection must separately confirm component compatibility, joint facing, bolting and materials.