Table 341.3.2 Acceptance Criteria for Welds and Examination Methods for Evaluating Weld Imperfections (Cont'd)

NOTES:

(1) Criteria given are for required examination. More stringent criteria may be specified in the engineering design. See also paras. 341.5 and 341.5.3.

(2) Longitudinal groove weld includes straight and spiral seam. Criteria are not intended to apply to welds made in
accordance with a standard listed in Table A-1 or Table 326.1. Alternative Leak Test requires examination of these welds; see para. 345.9.

(3) Fillet weld includes socket and seal welds, and attachment welds for slip-on flanges, branch reinforcement, and
supports.

(4) Branch connection weld includes pressure containing welds in branches and fabricated laps.

(5) These imperfections are evaluated only for welds less than, or equal to; 5 mm (3/16 in.) in nominal thickness.

(6) Where two limiting values are separated by "and," the lesser of the values determines acceptance. Where two sets of values are separated by "or," the larger value is acceptable. Tw is the nominal wall thickness of the thinner of two components joined by a butt weld.

(7) Tightly butted unfused root faces are unacceptable.

(8) For groove welds, height is the lesser of the measurements made from the surfaces of the adjacent components; both reinforcement and internal protrusion are permitted in a weld. For fillet welds, height is measured from the theoretical throat, Fig. 328.5.2A; internal protrusion does not apply.

(9) For welds in aluminum alloy only, internal protrusion shall not exceed the following values:
(a) for thickness less than, or equal to; 2 mm (5/64 in.): 1.5 mm (1/16 in.);
(b) for thickness > 2 mm and less than, or equal to; 6 mm (1/4 in.): 2.5 mm (3/32 in.).
For external reinforcement and for greater thicknesses, see the tabulation for Symbol L.

I'll happily explain, but this runs along the same lines as trying to apply visual acceptance criteria to internal weld surfaces when using a borescope or similar... the Code is being wrongly applied in these cases.  There ya go, black and white! 

My EDIT was to correct the symbols as best I could.