... flange; 3, the ring butt weld should be used full penetration weld; 4, the ring butt weld should be post-weld heat treatment, and for 100 ... flat welded flange with a neck and a high butt weld strength, which is less prone to leakage. High-quality products ... easy to distortion, good sealing, widely used, butt thinning transition weld joints ,horn shape, avoid shape change when welding in high ...