Section 195.212 - Bending of pipe(a) Pipe must not have a wrinkle bend.(b) Each field bend must comply with the following:(1) A bend must not impair the serviceability of the pipe.(2) Each bend must have a smooth contour and be free from buckling, cracks, or any other mechanical damage.(3) On pipe containing a longitudinal weld, the longitudinal weld must be as near as practicable to the neutral axis of the bend unless-(i) The bend is made with an internal bending mandrel; or(ii) The pipe is 123/4 in (324 mm) or less nominal outside diameter or has a diameter to wall thickness ratio less than 70.(c) Each circumferential weld which is located where the stress during bending causes a permanent deformation in the pipe must be nondestructively tested either before or after the bending process.Amdt. 195-22, 46 FR 38360, July 27, 1981, as amended by Amdt. 195-52, 59 FR 33396, June 28, 1994; Amdt. 195-63, 63 FR 37506, July 13, 1998