Density vs UTT

Date 11-16-2005 00:40

If you’re working to ASME B31.3 and inspecting to Table 341.3.2 and you have a weld that is rejected by x-ray for root concavity (suck back). There is a density change when comparing the suck back area and the base material. The suck back area is slightly darker. You instruct your NDE tech. to take a U.T D-meter and take a thickness reading in the suck back area and the readings show the weld thickness and the base metal are the same thickness. Using B31.3 Table 341.3.2 can you A. accept the weld. B. Is a densitometer a better instrument for making a determination like this? C. Does the 12.5% rule found in ASTM A 312/A (Table 3 permits variations in wall thickness). allow for more suck back?
Thanks
Jim

By MBSims

Date 11-16-2005 03:12

My interpretation of Table 341.3.2, assuming the weld thickness is equal to or greater than the thickness of the thinner or the two base metals being joined, is:

A. Yes.
B. No.
C. No.

By Jim Hughes (***)

Date 11-16-2005 14:41

Thanks for your responce Marty.
Why would the 12.5% wall loss rule not apply here?
Have you ever had to override a x-ray reject by using my reasoning about a D-meter being more accurate when determining weld thickness?
Jim