Pipeline weld inspection ratio
Thread Content
Regarding the inspection ratio for pipeline welds, SH 3501-2011 stipulates that \"the inspection of fixed weld joints should cover no less than 40% of the total number of inspections.\" Does the term \"total number of inspections\" in this clause refer to the combined total of prefabricated joints and fixed joints, or only to the fixed joints? I asked a few people, and their answers varied; I’m still a bit confused. In my opinion, in terms of welding quality, the welding quality of fixed joints is not as good as that of prefabricated joints; therefore, more emphasis should be placed on inspecting fixed joints during testing. If \"the number of inspections\" refers to the total number of both prefabricated and fixed joints, then there is no increase in the focus on inspecting fixed joints – in fact, it decreases. Hence, I agree more with the second viewpoint. I would like to ask fellow sailors which statement is correct, and please explain the reasons as well. Thank you!
Look at the standard meaning. . It is 40% of the fixed ports and needs to be tested. The original text states that the inspection of the welding joint fixation points should cover no less than 40% of the total number of inspections. The inspection of the welding joint fixation ports shall cover no less than 40% of the total number of inspections. The term “number of detections” corresponds to the previous “fixed-port detection”. . . By reasoning backwards, if there are 1,000 welds, and that represents 40% of the total number of welds required, then the total number of fixed welds might even be less than 400. .
This applies to pipelines with a random inspection ratio; it’s indeed not easy to understand. The welding conditions for fixed joints are not as good as those for pre-set joints, so more inspections are required. In my opinion, if there are 1,000 welds on a pipeline and the inspection ratio is 10%, then at least 100 welds need to be inspected. The inspection of fixed welding joints should cover no less than 40% of the total number of welds to be inspected. Among these 100, the number of fixed ports must be at least 40; in other words, the focus of inspection should be on the fixed ports. If it is understood that 40% of them need to be inspected, then the inspection of the welded joint fixed ports should cover no less than 40% of the total number of fixed ports.
According to this, 40% were inspected at the fixed ports and 60% at the prefabricated ports; it seems that the focus of inspection still wasn’t on the fixed ports. :)
In my opinion, this is a probability issue; the selection of testing points should be random, and it’s not possible to guarantee a specific proportion for different types of pipe ends. However, requiring that the proportion of fixed-end pipes be greater than 40% ensures an adequate amount of testing is carried out. For example, 20% prefabricated and 80% fixed is acceptable, whereas 20% fixed and 80% prefabricated is not. So the premise is still randomness
This post was last edited by Huddled together 421 on 2016-1-16 at 19:37. . . . . . . . . . . . . . . . . . . . . . . . .
:lol:lol:lol:lol:lol:lol