With neck flat welding flange craftsmanship presentation? Welded flange forging or the general process made wrought. When using steel or steel manufacturing, must meet the following requirements: 1. welded flange shall be subject to ultrasonic testing, no delamination defects; 2. should cut steel strip along the rolling direction, by bending butt into?? ring, and the surfaces of the cylindrical ring is formed of steel. May not be directly machined into a steel plate welded flange with a neck; 3. Ring butt welds should be full penetration welds;? 4 ring butt weld should be post-weld heat treatment, and for 100% ray or ultrasonic testing, radiographic inspection and compliance with the requirements of Class II JB4730, ultrasonic testing accord. JB4730 Class I requirements. ?? Welded flange neck lateral slope should be less than 7o. Welded flange strict control during production and welding parameters to ensure that the production and use can give full play to the role and value. Flat welding flange level and technical requirements should be consistent with the corresponding requirements JB4726-4728 of. ? 1, PN 0.25MP-1.0MPa for carbon steel, austenitic stainless steel forgings allow the use of grade Ⅰ forgings. ? 2. In addition to the following provisions, as 1.6MPa-6.3MPa, PN forgings shall comply with the requirements of forging grade Ⅱ Ⅱ grade level or above. ? 3. Meet one of the following circumstances, should conform Ⅲ and forgings requirements: (1) Nominal PN≥10.0MPa flange forgings; (2) Nominal pressure PN> 4.0MPa of chromium molybdenum steel forgings;??? (3) Nominal pressure PN> 1.6MPa and ≤-20 ° C operating temperature of ferritic steel forgings.