(a) Welding must be performed by qualified welders employing qualified welding procedures. Welders and welding procedures shall be qualified in accordance with API Standard 1104 (as set forth in section 10.3 of this Title) or section IX of the ASME Boiler and Pressure Vessel Code (as set forth in section 10.3 of this Title).

(b) Notwithstanding the pressure and temperature limitations contained in ASME B31.1-1989, welds subjected to temperatures over 350°F (175°C) shall be subject to nondestructive testing by radiographic inspection in accordance with subdivisions (c) and (d) of this section.

(c) All field welds in new steam pipeline installations and all prefabricated shop welds shall be nondestructively tested.

(d) Field welds made on existing steam pipeline facilities shall be subject to a program of random unannounced nondestructive testing to assess the quality of welding and test the work of each welder. The required minimum testing rate shall be 10 percent of all welds made during a calendar month. If 10 percent or more of the welds tested in a calendar month are found to be unacceptable, the test rate shall increase by five percent for the ensuing calendar month. If fewer than 10 percent of the welds are found to be unacceptable in a month where the required test rate was greater than 10 percent, the test rate may be decreased by five percent for the ensuing calendar month.