A branched pipe joint has been used to perform the pressure control, condition check, purgation, and distribution of the gas in the natural gas transmission facilities. Installation of branch pipes is generally done by the welding work, and as a welding process, there are the weldolet (the butt welding process) and the sockolet (the fillet welding process). During the maintenance working of in-service natural gas pipeline, there was gas leakage in sockolet weldment. The causes of incident were investigated with various tests. From chemical composition analysis, tensile test, hardness test, macro and micro structure analysis and fractography analysis, the wrong pipe material, the weld defect and the non-destructive test limitation of fillet weldment has been found as the reasons of weldment failure and gas leakage. As the follow-up measures, it was done to assess the weldment soundness of the sockolet and weldolet weld zone depending upon the configuration of the weld zone, a change in the welding process and a change in the pipe diameter. In the socket weld, the tensile strength showed no difference depending upon a change in the welding process and the fatigue strength showed a difference.
A study of failure case in fillet weldment of natural gas transmission facility
Eine Studie von Schadensfällen in Kehlnahtschweißverbindungen von Erdgasfernleitung
2008
5 Seiten, 10 Bilder, 9 Quellen
Conference paper
English
Fatigue Strength of Load-Carrying Box Fillet Weldment in Ship Structure
British Library Conference Proceedings | 2001
|