What causes cracks to appear during the welding of stainless steel ball valves?

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　　Stainless steel ball valves are primarily used in pipelines to shut off flow, distribute it, and change the direction of the fluid. They can be closed tightly with just a 90° rotation and a very small amount of torque. Ball valves are suitable for use as switches and shut-off valves. 　　Since ball valves typically use rubber, nylon, and polytetrafluoroethylene as materials for the valve seat seals, their operating temperature is limited by the material of these seals. The shut-off function of a ball valve is achieved by the metal ball pressing against the plastic seat under the influence of the medium (in the case of a floating ball valve). Under the contact pressure exerted by the valve seat seal ring, elastic-plastic deformation occurs in localized areas. This deformation can compensate for the manufacturing accuracy and surface roughness of the sphere, ensuring the sealing performance of the ball valve. Stainless steel ball valves can be installed in various ways, such as clamp-on, flange, threaded, and welded. Depending on the usage environment and preferences, the valve connection method can be selected. 　　Some issues that can arise during the welding of stainless steel ball valves; when welding such valves, it is important to remember the proper selection of the valve type. If it’s WCB, we choose the national standard grade, such as A3; other grades with high manganese and carbon content tend to crack during welding. Or during welding, the valve body may break or develop visible cracks. For stainless steel ball valves, we should choose materials of 304 or higher grade. This ensures safety during valve welding as well as stable and safe operation in the long term. What causes cracks to appear during the welding of stainless steel ball valves? 1. It is due to an excessively high welding current. Or argon arc welding was not chosen, which caused the stainless steel to develop cracks due to changes in the intergranular density at higher temperatures ； 2. The material quality of the valve body itself is an issue; due to its high carbon content, the high hardness of this material causes cracks to appear in the stainless steel when it is exposed to high temperatures during welding. 　　Therefore, when choosing stainless steel ball valves, it is necessary to avoid cracks or quality issues; one should opt for reputable manufacturers and ensure that the valves are made of 304 material that meets **standards. And a material quality certificate must be provided.