AD 2000 HP 5/3 pointed out:
"Welded joints shall be visually examined before nondestructive tests are performed.
Fusion welds shall be tested as a function of the material group, wall thickness s and use of the permissible design stress in accordance with the test methods, test categories and scope of testing specified in Tables 1b, 2b and 3b of AD HP 0."
The assignment of the material to the material group is listed in table 1a, 1b and 1c of AD HP 0-