1.In addition to 24 inches oil pipeline interfaceand 20 inches, 24 inches, 30 inches. 2.But according ... need to customize. 1.In addition to 24 inches oil pipeline interfaceand 20 inches, 24 inches, 30 inches. 2.Use, used ... , easy to welding and other characteristics, widely used in petroleum pipeline connection. 3.Process: forging, rough machining, heat treatment, inspection, finishing ...