What should be considered when repairing castings?
Thread Content
What considerations are needed when repairing castings? Casting defects are something that is quite common in valve manufacturing plants. Repair work should undoubtedly follow the principles of welding procedure qualification and post-welding inspection. Does this mean that welding is not allowed in valve assembly plants? Or is heat treatment necessary for welding repairs? How do valve manufacturing plants handle the repair of valve body castings? In other words, in valve manufacturing, how can quality issues related to casting be identified at various stages, and how should they be addressed? 1. Inspection stage upon receipt of materials: 2. Machining stage: issues such as black skin, cracks, as well as looseness in the sealing surfaces and clusters of pores; 3. Hydrostatic testing stage: leakage in the valve body
Valve manufacturers inevitably encounter castings with casting defects; these can be repaired by welding, but it is necessary to use the appropriate welding techniques. Heat treatment is crucial, as multiple welding attempts often do not yield good results