46 C.F.R. § 154.182
If a portion of the contiguous hull structure is designed for a temperature colder than −34 °C (−30 °F) and is not part of the secondary barrier, each 100m (328 ft.) of full penetration butt welded joints in that portion of the contiguous hull structure must pass the following production weld tests in the position that the joint is welded:
2 The most critical location in the heat affected zone of the weld is based on procedure qualification results, except austenitic stainless steel need have notches only in the center of the weld.