(b) For pipe that is manufactured in accordance with a specification not listed in section I of Appendix 14-B of this Title and whose specification or tensile properties are unknown, the yield strength to be used in the design formula in section 255.105 of this Part is one of the following:

1. (1) if the pipe is tensile tested in accordance with section II-D of Appendix 14-B to this Title, the lower of either 80 percent of the average yield strength determined by the tensile tests, or the lowest yield strength determined by the tensile tests; or
2. (2) if the pipe is not tensile tested as provided in paragraph (1) of this subdivision, 24,000 psi (165 MPa).