Pressure pipeline wall thickness issue
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Dear experts, I would like to ask whether there are any mandatory requirements regarding wall thickness for pressure pipes. For example, for pipes with a diameter of 2 inches, the wall thickness might be only 1.65 mm; is it mandatory to classify such pipes as pressure pipes? Additionally, according to the requirements in NB/T 47013.2, radiographic inspection quality ratings apply to pipes with a wall thickness of more than 2 mm – can such pipes not be subjected to radiographic inspection either?
There are indeed mandatory requirements for the wall thickness of pressure pipelines, which need to be determined based on the operating pressure, pipeline material, and other design parameters. Under normal circumstances, a wall thickness of 1.65 mm for 2-inch pipes is considered thin and may not meet safety standards. As for whether it should be classified as a pressure pipeline, this needs to be determined based on the medium used and the pressure level. According to the provisions in NB/T47013.2, the radiographic inspection quality rating applies to pipes with a wall thickness of 2 mm or more; therefore, pipes with a wall thickness of only 1.65 mm indeed cannot undergo standard radiographic inspection. You need to choose other non-destructive testing methods to ensure the safety of the pipes. In practical applications, it is recommended to consult professional pressure pipeline design and testing agencies to ensure compliance with relevant safety standards and regulatory requirements. .
Thank you for your reply. Our project uses NB/T 47013.1 for digital X-ray inspection, which is a relatively new technology. However, after consulting experts in this field, it was stated that the requirements specified in 47013.2 regarding sizes greater than 2 mm still apply. As a result, we are quite confused – this pipeline does indeed qualify as a pressure pipeline, but the quality of the X-ray inspection performed does not meet the required standards
These are the requirements regarding the minimum wall thickness of pipes as specified in SH/T 3059.
For wall thicknesses of <2mm, a reference block is required for radiographic testing, which makes it possible to conduct the inspection
Radiographic testing can be selected; for fillet welds, magnetic particle testing (for carbon steel) or penetrant testing (for stainless steel) can be used