Questions regarding pipeline flaw detection
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When the nominal diameter of the pipe is less than 500 mm, sampling inspections shall be carried out at the specified inspection rate based on the number of circumferential seams, with no fewer than 1 circumferential seam. Annular seam inspection should cover the entire circumferential length. The sampling inspection ratio for circumferential welds in fixed welding should not be less than 40%. Does the last sentence mean that as long as there is a fixed checkpoint, testing should be carried out at 40% regardless of the number of checkpoints? For example, if the inspection rate for pipeline testing is 5% and there are 40 inspection points, of which 30 are movable and 10 are fixed, then it should be 30*5% = 2 inspections for the movable points, and 10*40% = 4 inspections for the fixed points.
There should be a total of 2 inspections, with 1 inspection for the fixed joint; make sure that every welder covers their respective area.
Are there any standards that can be referenced?
This of yours covers every welder. . For the random inspection of fixed ports, 10*40% = 4 ports. . 1. The pipeline flaw detection rate is 5%. . 40*5% = 2. Now, 4 test pieces are being inspected, which is greater than 2. 2. The sampling rate for ring welds that are fixedly welded should be no less than 40%. 10*40%=4. All 4 inspection ports currently in use are fixed ports. 4=4, ..., all conditions are met. .
Ask those specifically in charge of supervision and inspection; they have different understandings of this matter. We usually consult the inspector before conducting flaw detection.
The inspection ratio for fixed openings should be 40% of the total ratio range.
Does that mean at least 4 access points need to be explored for this pipeline?
At least 4, of which 4 must be fixed ports
Is that passage in 50184 ambiguous? Either understanding is acceptable; the supervisor can mark the points as you say, but we’ll all conduct the inspection based on the percentage of the total number of points, which isn’t very convenient!
When the nominal diameter of the pipe is less than 500 mm, sampling inspections shall be carried out at the specified inspection rate based on the number of circumferential seams, with no fewer than 1 circumferential seam. Annular seam inspection should cover the entire circumferential length. The sampling inspection ratio for circumferential welds in fixed welding should not be less than 40%. This sentence is okay. . I don’t understand any other meaning.
You yourself made a mistake, didn’t you? . You have 40 welds, and you just picked 2 at random? The sampling quantity for this fixed port does not meet the requirements. .