Increase of allowable stress via xray in welded pipe
Increase of allowable stress via xray in welded pipe
(OP)
Given the scarcity of SEAMLESS pipe in 304-304L 16-inch sch.80, the question I have is: IF the longitudinal weld applied at the mill on WELDED pipe is given 100% x-ray inspection successfully, then can the allowable stress on the welded pipe be raised to ASME code value of 18,000 psi as in seamless pipe?
Thanks for your consideration.
Thanks for your consideration.





RE: Increase of allowable stress via xray in welded pipe
RE: Increase of allowable stress via xray in welded pipe
RE: Increase of allowable stress via xray in welded pipe
RE: Increase of allowable stress via xray in welded pipe
RE: Increase of allowable stress via xray in welded pipe
RE: Increase of allowable stress via xray in welded pipe
It is understood that welded pipe inspection at the mill is spot type.
Of course, efficiency and allowable stress are two different parameters, but they appear to be numerically proportional as the highest weld efficiency of 1.0 must match that of the parent metal. Since there is no welding present in seamless pipe, for example, it can be said the efficiency is also 1.0. If this is not the case, then what other physical parameter is the efficiency number measuring, especially in non heat treatable alloy like 304 stainless?
RE: Increase of allowable stress via xray in welded pipe
It appears to me, based on Sec II, Part D, Table 1A notes W12, W13, W14 there are some bases for using seamless allowable stresses for welded pipe. Detailed information about how the pipe is welded is needed, and may not be practical to get.
For most ordinary classes of work, I'd say, not worth pursuing.
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Increase of allowable stress via xray in welded pipe
RE: Increase of allowable stress via xray in welded pipe
.........pipe of a size larger than NPS 14 shall have a single longitudinal weld or shall be produced by forming and welding
two longitudinal sections of flat stock when approved by the purchaser. All weld tests, examinations, inspections, or treatments shall be performed on each weld seam.
Regards
r6155