A312/A358
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What are the specific inspection requirements for A312 welded pipes and A358 welded pipes, and which one has stricter requirements – A358? What is the difference between pipes with metal filler welding and those without it, and is it true that pipes with metal filler welding are necessarily better? Please help answer it
It can be understood that welding with filler metal means using a welding rod, while welding without filler metal means melting the metal directly?
1. A312 ① A312 is generally welded using TIG welding, without the addition of welding wire. ② No RT is performed on the welds; ET is used instead. ③ The welded pipes of A312 are generally made by welding steel coils or strips, which are long and thin. ④ The manufacturing units and A358 are also different. ⑤ Used for non-GC1 operating conditions. 2. A358 ① Plasma welding is used for A358 pipes without filler wire, while MIG and TIG welding are used when a filler wire is used. ② The steel pipe welds are fully penetrated double-sided or single-sided welds; in the case of single-sided welding, RT is used for all of them. ③ Welded pipes made of A358 are generally formed by rolling single steel plates, and they usually have a greater thickness compared to the steel coils or strips used for manufacturing A312. ④ It can be used in GC1 operating conditions.