CASES OF HIGH SPEED PINION VIBRATIONS AT LOW LOAD CONDITION IN API 613 TURBO GEARS

摘要

During operation of turbomachinery train used in oil & gas , petrochemical and refinery industries the selected gear box models are expected to show up vibrations within acceptable limits as mandated by API 613 standard or jointly agreed by OEM (Original equipment manufacturer) and End user for on-site operations. Based on these agreed values, reliability team sets up pre- alarm, alarm, and trip values. However, during low load operation during mechanical run test / coast down of a turbomachinery train, the pinion of speed increasing gear box may show up high vibration and cause concerns to end user. The proposed paper discusses several case studies where high vibration issues in turbo gear pinion were faced during various scenario such as API 613 mandated No / low load full speed run / during coast down or operating the train below actual speed map at site. With deep delving into the matter , the issues concluded as benign and non-intrusive to machinery integrity. The paper concludes with a point for requirement of deeper understanding to address such vibration phenomena during no load / coast down to decide whether issue to be considered as genuine or benign.