Regarding the issue of the welding coefficient
Thread Content
For GB150 single-sided welding (with a backing plate in close contact with the base metal along the entire length of the weld root), the weld coefficient for all non-destructive testing purposes is 0.9. Questions: 1. Since internal welding is not possible, can the RT100% TIG welding method using a backing plate be used to achieve a weld coefficient of 1.0? 2. Single-sided welding with double-sided formation is difficult to control; are there any other welding methods that can help achieve a weld coefficient of 1.0? 3. If the RT100% TIG welding method using a backing plate is employed and the weld coefficient remains at 0.9, how can adjustments be made in the calculations to meet the requirement of a weld coefficient of 1.0?
1. Since internal welding is not possible, the RT100% argon arc welding with backing plate method is used; can the welding coefficient meet the requirement of 1.0? No, the standard value is 0.9. 2. Achieving good double-sided formation through single-sided welding is difficult to control. Are there any other welding methods that can enable a welding coefficient of 1.0? For argon arc welding, achieving double-sided formation through single-sided welding is not difficult and constitutes a basic skill. To meet the 1.0 coefficient, it is necessary to achieve double-sided formation with single-sided welding, or to perform double-sided welding. 3. If the RT100% method with backing plate TIG welding is used, the welding coefficient is 0.9; how should adjustments be made in the calculations to meet the requirement of a welding coefficient of 1.0? You want to force it. . .
3. If the RT100% method with backing plate TIG welding is used, the welding coefficient is 0.9; how should adjustments be made in the calculations to meet the requirement of a welding coefficient of 1.0? I don’t understand what the original poster is trying to convey here – can the welding joint coefficient be adjusted through calculations? For single-sided welded joints with gussets, all were found to meet Grade II requirements; the joint coefficient can only be 0.9. Regardless of the welding method used, if the joints meet Grade III requirements, the joint coefficient is 0.8
Thank you to the person on floor 2 for the detailed response: handshake
Why is a backing plate needed for TIG welding as a base layer? So many pipeline welds can only be welded from one side; using TIG welding for the base layer is a fundamental skill. If a backing plate is still required for TIG welding as a base layer, then such a manufacturing plant should not engage in the production of special equipment. . . :P
Use a backing plate for TIG welding as a base layer. . . There are some too. . . Such as aluminum alloy. . :lol
I’ve experienced it before – I built an aluminum alloy silo many years ago; I’ve forgotten about it now: lol
It’s hard to say, especially with materials like stainless steel – the requirements for welders differ significantly depending on whether shims are used or not. For other items such as non-ferrous metals, not much work has been done and there is a lack of experience; cushion plates are definitely good
The key issue is the poor fit between the gasket and the cylinder or head; there is generally a gap, and during welding slag can easily penetrate into this gap between the gasket and the workpiece, resulting in defects that are visible in X-ray inspections.
What you say makes sense as well; the skill levels of welders vary greatly