What qualifications are required?
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I would like to ask: the main pipe has specifications of φ325×28, while the branch pipes have specifications of φ39×5; the material used is 12Cr1MoVG. What qualifications are required to weld such joints? Also, what qualifications are needed if no bevel is applied to these joints? Thank you
If it is to be used on pressure vessels or pressure pipelines, a welder’s certificate for pressure vessels is required; otherwise, no such qualification is necessary. Whether to make a groove is determined by the welding engineer as part of the welding process; it seems to have little to do with qualifications.
According to the diagram, pipes with a diameter of 76 or less and made of the same material are qualified for butt welding, allowing the branch pipes to be welded. If there is no groove, one can create one oneself. Really, if a groove needs to be made and the connection method changed to a butt joint, then qualifications for welding pipe sheets made of materials suitable for grades below 76 are required, which increases the difficulty of construction.
The welder’s grade corresponds to the pipe’s grade; for other tasks, the welding procedure qualification applies
It seems that a welding qualification has nothing to do with welding assessments
For the joint type shown in the diagram, can qualifications for pipe butt welding be used – 2G, 5G, and 6G are all acceptable. If there is no bevel, then must qualifications for pipe fillet welding be used? Are 2F and 5F suitable in that case?
The qualifications required for operation permits are determined based on the welding assessment criteria; Pwps
This welded joint is a fillet weld, a butt weld. Logically, it should be the FG tube sheet welder who performs the welding, but in most factories, welders with qualifications for butt welding are used for this task.
Position 2G is sufficient as shown; ideally, all positions should be 6G； The plug-in diagram is 2FG; 6FG in all positions is preferred (tube sheet fillet weld).