Welded shutter for hot blast valves - where outer ring is shrunk onto discs to form lap joints prior to welding

摘要

A ring weld is made between two workpieces, esp. two ring weld made between the two legs of a U-shaped ring and two circular discs in the mfr. of a sliding shutter used in a valve on a hot wind duct, e.g. in a blast furnace plant. Radial overlapping is provided for both joints, and the ring is heated before assembly so its radial expansion slightly exceeds the radial overlap. The ring is then pushed over the two discs and cooled to form the lap joints at the seams which will be welded. Instead of heating the ring, the two discs may be cooled before assembly. The ring is then pushed over the discs and the correct lap joint are obtd. when the discs return to room temp. Used for welding metal parts together to make a sliding shutter. The parts are correctly aligned and centered prior to welding, and a base is provided at the root of the welds by the lap joints, so strong welds are obtd.