| 摘要 |
PURPOSE:To improve the working property in sealing work by a method wherein grooves extending radially are provided in a washer and an inert gas filling port is provided at a shell flange so as to be able to fill inert gas at the welding of a seal cap. CONSTITUTION:Grooves 25 are formed on the side of the surfaces of a washer contacting with the upper surface of an upper tube plate 6 and the filling port 27 of argon gas to be filled as purge gas is provided at the shell flange 5. In order to perform sealing work, firstly, a bolt cap 22 is placed on a cylindrical body 21 made integrally with the upper tube plate 6 and temporarily connected with the body 21 by applying adhesive tape at the part to be welded later; secondly, the upper tube plate 6 is temporarily connected with the shell flange 5 by means of a seal bellows 23 by applying adhesive tape at the portion to be welded later; finally, argon gas is filled and at the same time, at first the seal bellows 23 is welded and then the beveled part formed between the cylindrical body 21 and the bolt cap 22 is welded from outside gradually by peeling off the tape little by little. |
