HAR 6-77-99 Wrinkle bends in steel pipe

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 sixteen inches or larger in diameter, the bend may not have a deflection of more than 1-1/2E for each wrinkle; and (4) On pipe containing a longitudinal weld the longitudinal seam must be as near as practicable to the neutral axis of the bend. [Eff ] (Auth: HRS '269-6) (Imp: 49 C.F.R. '192.315, October 1, 1990)