Questions about welding
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Which standard specifies which welding methods should be used for pressure vessels and pressure pipelines under different media or pressure levels?
It depends on the specific welding method and the operational condition constraints it has.
It won’t be specified in such detail. . Unless specified by individual industry standards. .
It seems that the welding method to be used has nothing to do with the pressure and the medium inside the container, and there are no regulations on this aspect in the standards either. The welding method to be used should be determined by the material, the thickness of the welded parts, and which components are being welded together.
I haven’t seen any standard requirements regarding the thickness of the welded parts, their material, or the relationship between different components that are welded together.
The design standards specify particular types of weld joints, which are related to the plate thickness and location, but not to the medium.
The welding method to be used should have nothing to do with the pressure and the medium inside the container; it seems that there are no regulations on this aspect in the standards either. The welding method to be used should be determined by the material, the thickness of the weldment, and the welding position.
The key is to see if the weld assessment is satisfactory; if it is, then it can be used. However, at present, products such as cored wires have unstable quality, so caution is needed when using some domestic welding materials.
But I seem to have seen it somewhere before, or perhaps the instructor mentioned during a training session that for materials exposed to high stress and containing toxic substances, welding with electric arcs is not allowed; instead, TIG welding should be used. However, I can’t find where this standard comes from
The term \"welding method\" isn’t very accurate, but what I can tell you is that Article 3.2.2 of TSG21-2016, the \"Safety Technical Inspection Regulations for Fixed Pressure Vessels\", provides detailed specifications regarding the types of weld joints in pressure vessels. For pressure pipelines, it is mainly the circumferential butt joints that are used, and generally a butt joint with full-thickness penetration welding should be adopted. As for which welding method to choose, there are no clear regulations stipulating this.
Just follow the company’s welding procedure qualification!