Equipment longitudinal circumferential weld joint coefficient
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When working on a U-shaped stamping machine for an overseas project, the client’s requirements regarding weld inspection were as follows: 100% non-destructive testing was required for longitudinal welds, while partial non-destructive testing was sufficient for circumferential welds. Since longitudinal stresses and circumferential stresses are different, I think this requirement put forward by the client is quite reasonable. However, when performing calculations, the welding joint coefficient is usually set at 1; in this case I used a value of 1 as well, which increased the inspection requirements for circumferential welds. I would like to ask everyone: if you were to work on this equipment, how would you approach it?
I think we should go with the higher value; generally, the strictest standard is followed.
If I choose the higher value, or if I choose the lower one, what if the longitudinal welds don’t meet the requirements?
According to UG-116, that is RT2. I work in NDT.
When using PVELite, the coefficients for longitudinal and circumferential weld joints can be entered separately; however, the common practice is to use the value for the longitudinal direction
ASME, EN13445, and AD2000 all support the scenario mentioned by the poster; in each of these standards, a value of 1.0 is used. AD2000 does not require 100% coverage for longitudinal girth welds – only 100% coverage for longitudinal welds, 100% coverage for T-joint welds, and 25% coverage for girth welds. In ASME, this corresponds to RT2； Group 2 for testing in EN13445
Our approach is to use a low value; the calculated thickness will definitely increase! Flaw detection must also be carried out to high standards! This is the most conservative approach
100% flaw detection is required for welds, with a weld factor of 1; 1 can also be used for 100% flaw detection of longitudinal seams (in foreign countries), as the strength calculation formulas are based on the strength exerted on longitudinal welds.
I’m here to learn *; please give me lots of guidance
It’s a quite standard approach; in PV calculations, the longitudinal ring welds are treated as separate elements