When the steel plate to manufacture flange, must meet the following requirements:
1 steel plate by ultrasonic flaw detection, without delamination defects;
2 steel rolling along the bias cut into strips, by bending welded into a ring, and the ring formed on the surface of steel cylinder. May not take the steel plate directly machined into the neck flange;
3 ring butt weld should be taken full penetration weld;
4 ring butt weld should stop after welding heat treatment, and 100% radiographic or ultrasonic testing, and radiographic fit II JB4730 request, JB4730 I with ultrasonic inspection request.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)