(c) A welder qualified under section 255.227(a) of this Part:

1. (1) may not weld on pipe to be operated at a pressure of 125 psig or more unless within the preceding 6 calendar months the welder has had one weld tested and found acceptable under section 6, 9, 12 or Appendix A of API Std 1104 (as described in section 10.3 of this Title). Alternatively, welders or welding operators may maintain an ongoing qualification status by performing welds tested and found acceptable under the above acceptance criteria at least twice each calendar year, but at intervals not exceeding 7½ months. A welder or welding operator qualified under an earlier edition of a standard listed in section 10.3 of this Title may weld, but may not requalify under that earlier edition; and
2. (2) may not weld on pipe to be operated at a pressure less than 125 psig unless the welder or welding operator is tested in accordance with paragraph (c)(1) of this section or re-qualifies under paragraph (d)(1) or (2) of this section.

(d) A welder qualified under section 255.227(b) of this Part may not weld unless:

1. (1) within the preceding 15 calendar months, the welder has requalified, except that the welder or welding operator must requalify at least once each calendar year; or

2. (2) within the preceding 7½ calendar months, but at least twice each calendar year, the welder or welding operator has had:

   1. (i) a production weld cut out, tested and found acceptable in accordance with the qualifying test; or
   2. (ii) a production weld tested and found acceptable under section 6 of API Standard 1104 (as described in section 10.3 of this Title); or
   3. (iii) for welders who work only on service lines two inches (51 millimeters) or smaller in diameter, two sample welds tested and found acceptable in accordance with the test in section III of Appendix 14-F to this Title.