I have some questions regarding pressure vessel welder qualifications and process qualification; I would appreciate guidance from experts
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This post was last edited by sh373347304 on 2018-6-21 at 16:40. First question: Ignoring the welding materials for now, for TIG welding of Q345R material with two sheets each 6 mm thick welded in a flat position, the code is GTAW-FeⅡ-1G-6. For welding two pipes with an outer diameter of 42 mm and a wall thickness of 6 mm using horizontal rotation, the code is GTAW-FeⅡ-1G-6/42. I noticed in Note A-2 of the TSG6002 standard that the codes for sheet butt welding can also be applied to pipe butt welding where the outer diameter is 76 mm or more. So if I use two sheets of material to roll into a cylinder with an outer diameter of 400 and a wall thickness of 6, and then join them together, would GTAW-FeⅡ-1G-6 be sufficient for that? Second question: According to 6.3.3 of NB/T47014, when a welding process that has passed the combined assessment is used for welding, one or more welding methods (or welding processes) may be employed, provided that its critical factors and supplementary factors remain unchanged. Only the base metal thickness of the test piece evaluated using any one of the welding methods (or welding processes) is required to determine the effective range of thicknesses for the base metal of the combined evaluation test pieces. Existing process qualification A: For Q345R plates with a thickness of 4 mm, the applicable range is 2–6 mm; a combination of GTAW and GMAW methods was used for qualification. Then, for welding the fillet welds between 20# pipes with an outer diameter of 12 and a wall thickness of 2 mm and Q345R plates with a thickness of 6 mm, all using GTAW welding, can Process Assessment A be employed?
There’s no problem with the first question; GTAW-FeⅡ-1G-6 can handle both Type A and Type B welds. Second question: The base metal thickness covered by the process qualification is 2–8 mm, and the total thickness of the welds covered is 0–8 mm. The base metal thickness of the fillet weld is 2 mm and 6 mm, while the weld thickness is 6 mm. If you are using all-tungsten arc welding, you can cover this fillet weld. If it is a combined assessment, the base metal thickness and weld thickness covered are separate. For a 4mm thick base metal of the test piece, assuming that the weld thicknesses for GTAW and SMAW are 2mm respectively, the scope of this process qualification should cover a base metal coverage range of 2~8mm for GTAW and a weld thickness range of 0~4mm; for SMAW, it should cover a base metal coverage range of 2~8mm and a weld thickness range of 0~4mm as well. The thickness of your fillet weld is 6 mm; therefore, in your process qualification, the weld thickness for TIG welding must be 3 mm, so that the total weld thickness ranges from 0 to 6 mm, thereby covering this fillet weld. PS: Another prerequisite for coverage is that the strength of the wire used for the fillet welds must not be lower than the strength of the wire specified in the process evaluation. (Article a of 6.1.3.1)
On the second floor, I remember that fillet welds are not related to the thickness of the weld joint; what you’re referring to are the combined welds in corner joints, which are indeed related to thickness
On the second floor, I remember that fillet welds are not related to the thickness of the weld joint; what you’re referring to are the combined welds in corner joints, which are indeed related to thickness
A fillet weld that is independent of the weld thickness is classified as a Type E weld; in the case mentioned, it is an insertion weld between a pipe and a cylinder, which falls under Type D, namely a combined fillet weld.
This post was last edited by niat8888 on 2018-6-26 08:05. 1. Welder skill coverage, with limitations on outer diameter; mainly ring welds. . . Or the saddle-type branch pipe connection weld. . Therefore, this welder qualification can be used; 2. This assessment is conditional for use. . However, in the case of groove welds, if all of them are welded using GTAW, the thickness of the weld metal will not be sufficient. If it’s a fillet weld, there’s no problem at all
The original poster is asking where it can be determined that a fillet weld belongs to category D; I don’t see any indication of category D anywhere