Wrinkle bends in steel pipe.

(a)A wrinkle bend may not be made on steel pipe to be operated at a pressure that produces a hoop stress of 30 percent, or more, of SMYS.#

(b)Each wrinkle bend on steel pipe must comply with the following:#

(1)The bend must not have any sharp kinks.#

(2)When measured along the crotch of the bend, the wrinkles must be a distance of at least one pipe diameter.#

(3)On pipe 16 inches (406 millimeters) or larger in diameter, the bend may not have a deflection of more than 1 1/2° for each wrinkle.#

(4)On pipe containing a longitudinal weld the longitudinal seam must be as near as practicable to the neutral axis of the bend.#