The requirements of 8.8.2.2 in GB/T150-2014 shall be subject to the process evaluation specified in NB/T47014-2011; however, the process evaluation for heat exchange tubes in NB/T47014-2011 applies to strength welding as well as expansion welding.
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Clause 8.8.2.2 of GB/T150-2014 requires that welds resulting from strength welding and internal hole welding be subject to process qualification in accordance with NB/T47014-2011. Appendix D of NB/T47014-2011 provides specific process qualification procedures for heat exchanger tubes and tube sheets, and these procedures are applicable to welds made by strength welding or expansion welding; therefore, is the process qualification for strength welding also carried out according to these procedures?
This post was last edited by wanlirn on 2023-4-8 at 09:46. Please pay close attention to the standards: Appendix D contains the relevant regulations regarding additional weld evaluations. In cases that do not fall under Appendix D, a weld evaluation for the connection between the tubes and the tube sheet is still required. According to Professor Ge, the author of the standards, welding between tubes and the tube sheet must meet the requirements for fillet welds, regardless of whether bevels are used or not; therefore, either a weld evaluation for fillet welds or one for butt welds is needed