Seeking advice regarding the weld evaluation for pressure vessels
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I’m just starting to work with this area, and I’d like some **guidance**. 1. If 8mm thick Q345R steel plates are to be joined together, using TIG welding for the root pass and submerged arc welding or arc welding for the cover pass, can the weld evaluation be conducted using a 5mm thick TIG-welded joint test piece, along with an additional 8mm thick submerged arc welding or arc welding joint test piece? 2. If the cylinder is welded to the tube sheet, with a 16Mn tube sheet having a thickness of 42 mm and a Q345R cylinder having a thickness of 8 mm, argon arc welding should be used for the root welding while arc welding is used for the overlay welding. The weld evaluation requires testing at both thickness levels; therefore, could it be done by using a 5 mm thick argon arc welding test piece, an 8 mm thick arc welding test piece, and a 20 mm thick arc welding test piece? Is it still necessary to make a 13mm TIG welding butt joint test plate?
This post was last edited by niat8888 on 2016-6-1 08:13. Question 1: For 1.5 mm GTAW base material, the coverage range is 2.5–10, and the thickness of the deposited metal is 0–10. For 2.8 mm SMAW base material, the coverage range is 8–16, and the thickness of the deposited metal is 0–16. By combining these two sets of parameters, a welding procedure can be formulated. Question 2: For 1.8 mm GTAW base material, the coverage range is 8–16, with a deposited metal thickness of 0–16. For 2.13 mm GTAW base material, the coverage range is 13–26, and the deposited metal thickness is 0–26. (Table 9 is used here; the upper limit for the base material range has been increased.) For 8 mm SMAW base material, the coverage range is 8–16, with a deposited metal thickness of 0–16. For 38 mm SMAW base material, the coverage range is 16–200, and the deposited metal thickness is 0–200. By combining these four evaluations, a welding process can be defined in this way
Thank you so much. I have two more questions and would appreciate it if you could help answer them. I’m completely confused by the standards. If the tube sheet has a thickness of t=42 mm, is made of 16Mn forged to grade 2, the heat exchange tubes are 25*2 in size and made of S30408, and a strong weld along with expansion jointing is required, then can the weld assessment be carried out in this way? 1. Perform butt welding (TIG welding) of S30408 and 16Mn plates with a thickness of t=5. 2. Perform another butt weld (SAW welding) of S30408 and 16Mn plates with a thickness of T=25mm. 3. Conduct an additional assessment for a tube sheet with dimensions of 25*2 and a thickness of t=25. Is TIG welding also required for the second task? Ask questions for answers
Is it possible to do a combined assessment? 3mm GTAW for the root pass and 5mm SMAW for the cover pass; the penetration depth for the base material is 1.5–6 mm with GTAW, and 1.5–10 mm with SMAW.
Correction: The SMAW thickness range should be 2.5–10, is that okay?