49 CFR §192.243

1. (a)Nondestructive testing of welds must be performed by any process, other than trepanning, that will clearly indicate defects that may affect the integrity of the weld.
2. (b)Nondestructive testing of welds must be performed:
   1. (1)In accordance with written procedures; and
   2. (2)By persons who have been trained and qualified in the established procedures and with the equipment employed in testing.
3. (c)Procedures must be established for the proper interpretation of each nondestructive test of a weld to ensure the acceptability of the weld under § 192.241(c).
4. (d)When nondestructive testing is required under § 192.241(b), the following percentages of each day's field butt welds, selected at random by the operator, must be nondestructively tested over their entire circumference:
   1. (1)In Class 1 locations, except offshore, at least 10 percent.
   2. (2)In Class 2 locations, at least 15 percent.
   3. (3)In Class 3 and Class 4 locations, at crossings of major or navigable rivers, offshore, and within railroad or public highway rights-of-way, including tunnels, bridges, and overhead road crossings, 100 percent unless impracticable, in which case at least 90 percent. Nondestructive testing must be impracticable for each girth weld not tested.
   4. (4)At pipeline tie-ins, including tie-ins of replacement sections, 100 percent.
5. (e)Except for a welder or welding operator whose work is isolated from the principal welding activity, a sample of each welder or welding operator's work for each day must be nondestructively tested, when nondestructive testing is required under § 192.241(b).
6. (f)When nondestructive testing is required under § 192.241(b), each operator must retain, for the life of the pipeline, a record showing by milepost, engineering station, or by geographic feature, the number of girth welds made, the number nondestructively tested, the number rejected, and the disposition of the rejects.