S9074-AR-GIB-010/278 with an enchant that has been demonstrated to disclose heat-affected zone structure in the material involved unless repair welding is required. Etchants shall be prepared and used in accordance with good metallurgical practice.
7.7.2 Excavations requiring repair welding shall be MT/PT examined or visually examined at 5X magnification, prior to repair welding, if MT/PT inspection is a requirement for the class of welding. Excavations requiring repair welding shall be
welded only to the extent necessary to restore minimum design thickness or to achieve a condition equivalent to acceptable depth and extent of weld undercut. Repair welds of excavations, if required, shall be inspected by the same NDT method as the original weld. Except where the repair welded excavation of previously accepted radiographed or ultrasonically tested welds does not exceed 3/16 inch or 20 percent of the base metal thickness, whichever is less, the repair may be MT/PT inspected in lieu of radiographic testing (RT) or ultrasonic testing (UT). The total thickness, repair weld plus base metal, shall be used for determining the approved acceptance criteria. See 13.2.8.1 for additional requirements for S-51, S-52, and S-53 materials. 7.8 Marking. Marking of welds for identification purposes, such as may be required in the mapping of joints, record keeping, and establishing responsibilities for workmanship and quality of welding, shall be done preferably with an electro-etch pencil or vibro-tool method. Where it may be necessary to retain identification markings and the electro-etch pencil or vibro-tool methods are inadequate due to the application of paint or other coatings which may tend to obliterate such marking, the low-stress round-bottom impression stamping method may be used in lieu of vibro-tool or electro-etch methods. Where the stamping method is used, impression should be placed on the thicker joint member, such as fittings in piping systems or the lowest stressed surfaces of other classes of welding. Pipe and tubing shall not be stamped. The maximum allowable depth of the impression shall be 0.01 inch and the impression tool shall be in accordance with the following requirements.
1/16 3/32 1/8 3/16 1/4 Character Size inches
0.005 0.006 0.007 0.008 0.010 Minimum character face radius inches
7.9 Defect removal. Defects, whether from weld or base material, may be removed by grinding, machining, or filing with clean tools. The removal process shall not deposit iron, lead or other deleterious contaminants on the surface of corrosion resistant material. For titanium and titanium alloys. see 7.2.2. If weld The depth of the impressions shall not reduce material thickness below the minimum thickness required by design. Marking shall be located so as not to interfere with interpretation of radiography .
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