PROCEDE DE FABRICATION D'UN ENSEMBLE DE STRUCTURE A INTERVALLES ETROITS

A method for assembling narrow gap members by welding is described. In the method, separate narrow gap members having spaces therein when assembled are provided and a deformation-preventive material consisting of a water-soluble material or a material capable of being disintegrated with water is filled in each space and is formed with a through groove or hole in the filled preventive material. In this state, the separate narrow gap members are subjected to welding, and immersed in water to remove the deformation-preventive material from each space. The through grooves may have a width larger than a leg length of each penetration bead, in which a heat-resistant flux is filled in each groove. The deformation-preventive material may be covered with a heat-resistant ceramic backing member shaped in a specific form or with a heat-resistant particle layer and a copper member shaped in conformity with an intended size and shape of a penetration bead.