Acoustic emission monitoring during hydrotesting of a mounded LPG storage vessel of petrochemical industry

摘要

One mounded LPG storage vessel of petrochemical plant got suddenly exposed to cryogenic nitrogen and developed cracks in the shell plate adjacent to the bottom nozzle and was subsequently repair welded. The structural integrity of the repair weld region was assessed by NDT examinations. The integrity of the repaired weld region was confirmed by conducting hydrotest. Acoustic emission (AE) monitoring during the hydrotest was also carried out. The acoustic emission signals generated during the hydrotest indicated that the signals were due to structural noise and microyielding of the vessel material. During the repressurizing cycle of the hydrotest, negligible AE signals were generated and this confirmed the structural integrity of the repair welded region of the vessel monitored by acoustic emission technique (AET).