Is surface inspection required for the tube sheet and heat exchange tube joints?
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Is surface inspection mandatory for the weld joints between the tube sheet and heat exchange tubes in austenitic stainless steel? Including surface inspection of the weld joint between the pipe flange and the pipe stub? Refer to the provisions of C in 10.4 of GB150.4
The requirement for C in 10.4 of GB150.4 is not the same concept as the weld described by the original poster!
I don’t really understand flange manufacturing! ! ! ! ! !
I believe that when GB/T151 is used for the calculation of tube sheets, surface testing is not mandatory; whereas when an analytical method is employed, surface testing should be specified in the design documents.
Flanges: Our company does not deal with surface inspection of welded joints in this area; perhaps it’s because our industry is different.
For the welding joints between the heat exchange tubes and the tube sheet, GB150 and GB/151 do not require surface non-destructive testing; however, since these welding joints are quite important, we generally specify surface testing during the design phase. The content of GB150.4 you posted is different from the printed version; the printed version does not mention \"pipe socket fillet welds\". The term \"pipe socket fillet weld\" was mentioned in 4.5.3.1 of the first version of Specification 99 when it was released, but it sparked many objections; subsequent revisions to the second version addressed this issue. What I want to say is that when using electronic standards, it’s essential to verify their accuracy; otherwise, it can be very harmful.
GB150 does not require surface inspection of all welded joints between nozzles and flanges, although there are certain special cases in which such inspection is required. It’s likely that you still have a misunderstanding regarding the concept of pipe socket fillet welds.
What the original poster is concerned about is whether it is mandatory. Firstly, this is crucial here; a leak can cause contamination of the medium. Then, in addition to PT, leaks here can also be detected through subsequent hydrostatic and airtightness tests. Personally, I think it’s better to conduct inspections during the manufacturing process; at least this way problems can be identified and resolved in advance. Especially for devices with many pipe ends, no one can guarantee 100% perfect welding.