joint-penetration welds shall be either radiographed (section 6, Part III) or ultrasonically examined (section 6, Part IV); partial penetration and fillet welds shall be examined by the magnetic particle method (section 6, Part V). Acceptance criteria shall be in accordance with the following.
The following acceptance criteria, in accordance with the procedures and standards of section 6, Part II, shall apply to all Class A welds, during visual examination for surface defects:
(1) The weld shall have no cracks, surface porosity, or entrapped slag as identified by the unaided eye.
(2) Complete fusion shall exist between adjacent weld beads, and between weld metal and base metal.
(3) All craters shall be filled.
(4) Weld profiles shall be in accordance with Figure 7.5(A), (B), or (D).
(5) Undercut shall be restricted for base metals of thickness t as follows:
(a) t > 25 mm (1 in.): Undercut shall not exceed 1.5 mm (1/16 in.) in depth, and the length of any undercut is not restricted.
(b) 6 mm (1/4 in.) s t s 25 mm (1 in.): Undercut shall not exceed 0.8 mm (1/32 in.) in depth, and the length of any undercut exceeding 0.4 mm (1/64 in.) in depth shall not exceed 50 mm (2 in.) in length in any continuous 300 mm (12 in.) of weld.
(c) t < 6 mm (1/4 in.): Undercut shall not exceed 0.4 mm (1/64 in.) in depth, and the length of any undercut shall not be restricted.
(6) The root surface of single-welded groove welds without backing that require complete joint penetration shall be inspected, where accessible, and there shall be no incomplete fusion or incomplete joint penetration.
(7) The maximum root surface underfill shall be 1.5 mm (1/16 in.), and the maximum melt-through shall be 3 mm (1/8 in.). The weld thickness shall be equal to or greater than that of the base metal.
7.10 Radiographic and Macroetch Test Acceptance Criteria
7.10.1 Radiographic Acceptance Criteria. The following acceptance criteria for Class A production and qualification welds, as applicable, shall be satisfied.
(1) The welds shall be free of cracks.
(2) If the base metal thickness, t, is 6 mm (1/4 in.) or less, the greatest dimension of any individual discontinuity shall be less than 3 mm (1/8 in.).
If t is more than 6 mm (1/4 in.) but less than or equal to 30 mm (1-3/32 in.), the greatest dimension of any indi vidual discontinuity shall not exceed two-thirds of the effective throat or two-thirds of the weld size.
If t is greater than 30 mm (1-3/32 in.), the greatest dimension of any discontinuity shall not exceed 20 mm (3/4 in.).
(3) No discontinuity shall be closer than three times its greatest dimension to the end of a groove weld subject to primary tensile stress.
(4) For a group of discontinuities in line, the sum of the greatest dimensions of all discontinuities in any portion of the weld equal in length to six times the effective throat or weld size, shall be less than the effective throat or weld size. When the length of the weld being examined is less than six times the effective throat or weld size, the permissible sum of the greatest dimensions shall be directly proportionate (i.e., 1/6 x effective throat or weld size.).
(5) The space between two adjacent linear discontinuities shall be at least three times the greatest dimension of the larger of the discontinuities in the pair being considered.
(6) Independent of the requirements of 7.10.1(2) through 7.10.1(5), the sum of the greatest dimensions of all discontinuities with a greatest dimension of less than 3 mm (1/8 in.) shall not exceed 10 mm (3/8 in.) in any continuous 25 mm (1 in.) of weld.
7.10.2 Macroetch Test Acceptance Criteria. Weld shall be free of cracks. Slag, porosity, or other defects exceeding 3 mm (1/8 in.) in height or width shall be cause for rejection. However, linear indications associated with the root of partial penetration joints and groove welds with backing bars are acceptable, provided such linear indications do not exceed 1.0 mm (1/32 in.), and provided such adjacent linear indications are separated by at least 3 mm (1/8 in.).
The acceptance criteria of 7.9 and 7.10 shall apply to nondestructive surface examination (magnetic particle, liquid penetrant, or eddy current) performed on Class A welds.
7.12 Ultrasonic Examination Acceptance Criteria
The Customer shall designate the Class, X or R, which applies to all welds to be examined.
7.12.1 Disregard all DRL (Disregard Level) indications having half (6 dB) or less amplitude compared to the standard sensitivity level (with due regard for 6.14.6).
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