| 摘要 |
PURPOSE: A method of repairing a labyrinth seal of a diffuser in a primary pump of a nuclear power station is provided to transform a portion of the stresses into deformation avoiding defects in proper operation of the primary pump, while reducing the risks of cracks forming on the lips of the labyrinth seal. CONSTITUTION: A method comprises the steps of making a bore in the circular end wall of diameter larger than an orifice(33) so as to withdraw a central portion(32a) of an end wall(32) and remove the labyrinth seal, reducing the thickness of a residual portion(32b) of the end wall around the bore, forming a chamfer on the edge of the bore, positioning a replacement part in the bore, wherein the replacement part includes a central orifice, and a chamber arranged in the peripheral edge of the part, providing a continuous and leakproof bead of welding between the two chamfers, making flush the flash on the bead of welding; and producing lips to form a new labyrinth seal in the central orifice of the replacement part.
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