Research status of vibration fatigue of girth weld of compressor outlet pipe

In recent years, China's natural gas industry has developed very rapidly, and its utilization scope and use areas have gradually expanded. A lot of natural gas station yards have been built all over the country. The girth weld of the compressor inlet and outlet pipeline in the station has been affected by high pressure and vibration fatigue for a long time during service, which is a weak link in the pipeline. In this paper, through field investigation of 4 compressor stations and 14 compressor units along a pipeline, 106 girth welds in the compressor area are identified. The structural characteristics of girth welds near the compressor are multiple diameter specifications, multiple wall thickness specifications, multiple butt types, different material butt joints, straight pipe-pipe fitting, straight pipe-valve, and unequal wall thickness butt joints. In addition, this paper summarizes and analyzes the current situation of pipeline vibration fatigue at home and abroad from the research hotspots, which include pipeline vibration control standards, compressor vibration, fatigue life design evaluation, and life prediction of vibration fatigue, etc. The fatigue life research of pipeline welds mainly focuses on butt welds of the same material in long-distance pipelines, and lacks the pertinency of compressor outlet girth welds.