Welding manufacturing technology method of large water turbine ball valve of all-welded structure

Abstract

The invention discloses a welding manufacturing technology method of a large water turbine ball valve of an all-welded structure. The method represents innovation of an assembly-welding technology method of the large water turbine ball valve of the all-welded structure and is the essential change of the manufacturing method. The technological scheme of coating high-temperature-resistant paint before assembly welding of a shaft sleeve as a welding auxiliary tool, a valve and a valve body single-piece and performing symmetric welding in the vertical welding position during rotating of the valve is applied for the first time, with the adoption of the method, accessibility and operability of welding are greatly improved, welding deformation is effectively controlled, quality of a ball valve welding seam is guaranteed by intermediate flaw detection, critical dimensional stability of the ball valve is guaranteed, and the assembly-welding quality of the large water turbine ball valve of the all-welded structure is remarkably improved accordingly.

Description

technical field [0001] The invention relates to a welding manufacturing process method of a large-scale fully welded structure water turbine ball valve. Background technique [0002] The valve body of the large-scale hydraulic turbine ball valve is divided into two or more valves. In the past, they were combined to form a whole, which requires high sealing quality. The connection is a whole, and there is no relevant manufacturing experience in China. The ball valve with fully welded structure has the advantages of light weight, good overall performance, and reliable sealing, but the manufacturing process is relatively complicated, and this type of ball valve is mostly used in the pressure pipeline of the hydroelectric generator set, and the quality of the weld seam is required to be high. The welding seam generally adopts double-sided groove filling welding, and the local maximum welding seam thickness in the structural welding seam can exceed 300mm. The quantity is large,...

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Problems solved by technology

The fully welded ball valve has the advantages of light weight, good overall performance, and reliable sealing, but the manufacturing process is relatively complicated, and this type of ball valve is mostly used in the pressure pipeline of the hydroelectric generator set, and the quality of the weld seam is required to be high

The welding seam generally adopts double-sided groove filling welding, and the local maximum welding seam thickness in the structural welding seam can exceed 300mm. The quantity is large, the operation is difficult, the weld quality and dimensional accuracy are difficult to guarantee, and the traditional assembly and welding technology cannot be used to complete the production.

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