Method for determining the welding joint coefficient of the reinforcement shell at the takeover opening
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Dear teachers, regarding the issue of whether the value for the welding joint coefficient at openings in SW6’s reinforcement calculations should be 1 or 0.85, I discussed this with the flaw detection team a couple of days ago: when an opening is located on a weld, if the cylinder meets the 20% requirement and is classified as grade III, then even if 100% flaw detection is carried out within the 2Dop area surrounding the opening, the acceptance level will still be based on the grade III standard of the main equipment. Therefore, I personally believe that the welding joint coefficient at such openings should be 0.85. Of course, it’s not clear whether there is a 20% tolerance for the shell, with grade III being considered acceptable; the 2Dop detection area around the opening has been increased to 100%, resulting in grade II being acceptable. If the 2Dop detection around the opening reaches grade II, it doesn’t need to follow the grade III standard for the cylinder body. I think it’s acceptable to assign a value of 1 to the shell at the opening site and 0.85 to the main cylinder body. What are your thoughts on this issue, dear colleagues?
I personally support your view! In reality, you should follow the cylinder’s specifications; at least different reviewers have different opinions, and you might even be required to make adjustments ； Follow the cylinder to avoid unnecessary hassle.
Your view is correct, but in actual design, no specific requirement is set for the acceptable level of flaw detection at the openings in the cylinder; therefore, our designs always use the values related to the welded joints of the cylinder