1: joint processing
In the design of the welded joint of the valve body, there is a ring-shaped fitting gap at the root of the weld, which will produce a stress concentration of several times the normal working stress under the internal pressure and external load. Making it difficult for engineers to deal with.
The stress concentration of the root gap of the welded joints of the valve body, the residual stress and the poor quality of the structure become the weak links in the valve body structure, and the valve industry is concerned at home and abroad, but there is no report about this problem. A hidden danger of structural boundary integrity.
2: heat treatment technology
The thick-walled multi-layer welding process is the process of repeated heating and cooling of the metal material, resulting in the unevenness and inferiority of the welded joint structure, resulting in higher residual stress and even welding defects. Welding is the product after the assembly of the last process, the valve cavity with non-metallic sealing material rubber and PTFE plastic, can not be post-weld heat treatment.