The issue of flaw detection ratio
Thread Content
Dear experts, I have a question regarding the inspection ratio for pipeline welds. SH3501 specifies a requirement for the proportion of butt welds to be inspected. Is this proportion calculated based on each pipe diameter individually, or is it determined based on the total number of welds? For example: if the inspection rate for a pipeline is 10%, and there are 5 joints of DN80, 5 joints of DN50, and 5 joints of DN25, should the inspection be conducted on 1 joint each of DN80, DN50, and DN25, or can any 2 joints be selected regardless of their diameter based on the total number? Please ask the experts for some guidance.
Generally, for the same welder, about 10% of the welds along a line need to be checked, and fixed joints also require attention
So, if the entire line is welded by the same welder, does flaw detection need to cover all the joints of each specification? Or can I just choose any specification as long as the number of tests for this line is sufficient?