Cause Analysis of Weld Crack of Pressure Vessel Attached to Gas Injection Compressor

Abstract

Through the technical analysis of many cracks and leaks occurred in the pressure vessel attached to the gas injection compressor during its long service period at high pressure, the chemical analysis, metallographic analysis, hardness measurement, finite element analysis and vibration monitoring of the three-stage outlet spherical tank were carried out. Finally, it is determined that the causes of the defects are the high hardness and stress values of the weld seam and heat affected zone of the nozzle, and the mechanical fatigue caused by the alternating load caused by the vibration of the unit.