Notch Ductility Requirements of Line Pipes for Arresting Propagating Shear Fracture

Full-scale burst tests were carried out on X70 line pipes, 48 in. o. d. × 0.720 in. w. t., with air and rich and natural gas as the pressurizing gases. The experimental results indicated that very high notch ductilities of pipes are required for arresting propagating shear fracture especially in the case of the rich natural gas. From theoretical investigations a method was developed which enabled the prediction of the required notch ductilities of line pipes with regard to the type of gas, design stress and acceptable fracture length.