2006 B31.3

344.6 Ultrasonic Examination
344.6.1 Method. Examination of castings is covered
in para. 302.3.3; other product forms are not covered.
Ultrasonic examination of welds shall be performed in
accordance with BPV Code, Section V, Article 4, except
that the alternative specified in (a) and (b) below is
permitted for basic calibration blocks specified in
T-434.2.1 and T-434.3.
(a) When the basic calibration blocks have not
received heat treatment in accordance with T-434.1.5,
transfer methods shall be used to correlate the responses
from the basic calibration block and the component.
Transfer is accomplished by noting the difference
between responses received from the same reference
reflector in the basic calibration block and in the component
and correcting for the difference.

It's still not in the table "yet" but it's headed that way given the 06 inclusion of the above paragraphs.
It may not be in the table yet, but it is definetly included in the below para.

341.4.3 Examination -- Severe Cyclic Conditions.
(b) Other Examination. All circumferential butt and
miter groovewelds and all fabricated branch connection
welds comparable to those shown in Fig. 328.5.4E shall
be examined by 100% radiography in accordance with
para. 344.5, or (if specified in the engineering design)
by 100% ultrasonic examination in accordance with para.
344.6. Socket welds and branch connection welds which
are not radiographed shall be examined by magnetic
particle or liquid penetrant methods in accordance with
para. 344.3 or 344.4.

Regards,
Gerald

Hi js55 and Gerald. I appreciate your frustration. I have recently started work on a B31.3 Chapter IX piping project dealing with very heavy wall pipework (up to 73mm) and it is frustrating that the ASME committee responsible for updating the B31's do not seem to want to fully integrate manual ultrasonics into the Code. Code Case 181 (almost identical to ASME Code Case 2235-9) exists for alternative ultrasonic acceptance criteria - basically ECA-derived and thus not suitable for manual ultrasonics (despite Appendix D-493 describing a method for manual through-wall defect height measurement with no mention of allowance for vertical beam spread which at 110mm sound path could be quite considerable if an 10mm dia, 2 1/2 MhZ probe is used!) By not clearly describing the methodology for manual ultrasonic inspection and evaluation of pressure vessel and pipe welds I think the ASME committee(s) are putting all the responsibility for interpretation on to the site technicians, Level III's and, possibly,  TPI's. I cannot fathom out why manual ultrasonics should be treated in this Cinderelaa fashion when occasionally it is the only effective inspection method.

ASME Code has me so confused and unable to discern clear and unequivocal requirements that I could think that the calibration blocks stipulated in T-434.3 "Piping calibration blocks" referred to examination of pipe material, to which they seem ideally suited, and not pipe butt welds (not so well-suited in my opinion), which are not mentioned at all in that paragraph. However as Article 4 is for ultrasonic examination of welds I have to accept that the intent is that this paragraph does apply to pipe weld inspection witht he consequence of a requirement for a range of calibration blocks corresponding to the range of pipe diameter/thickness configurations.

Another concern is that once a technician has worked out the acceptance criteria, it is still not clear (to me, at least) whether a measured length of slag (sing the 6dB drop) exceeding the length requirements of Table K341.3.2. but nowhere attaining a signal amplitude exceeding 100% DAC is cause for automatic rejection or not. Para. T-482.1 "Evaluation Level - Distance-Amplitude Techniques" requirement to investigate all indications greater than 20% DAC "to the extent that they can be evaluated in terms of the acceptance criteria of the referencing Code Section." suggests that it is not necessary for an indication to break the DAC curve to be rejectable. If an indication over 20% DAC is evaluated as a crack - repair. If an indication evaluated as slag exceeds the maximum permitted length and yet with an amplitude consistently above 20% but below 100% DAC, repair - else who will pick up the report at a later date and call for repair? Yet slag has a "real" geometry not necessarily favourably orientated to the ultrasonic beam as opposed to the artificial geometry of the calibration block notch (if used for senstivity setting) which presents an ideal corner reflector. Be happy to read your further thoughts, comments and experiences.