TRIP OF BOILER FEED WATER PUMP 10-P-8001A This is boiler feed waterpump is driven by ST through reduced gearbox. Operating speed of turbine is 4990rpm and pump is about 2900rpm. This pump is operated occassionally depending on the process requirement and steam. From 25/05 until 18/06/15 we make a major overhaul for all plant but do nothing for this pump. Before this starting on 18/06/15, this pump is operated normally with all parameter in acceptance. 18/06/15 we restart the plant and the pump is runned as required but it is tripped. - 1 st trip : we start the ST normally up to near 5000rpm, the pump is tripped due to high vibration at NDE ST, vibration at pump and gearbox is normal. As my opinion, it is by carbon seal make their seat and lead to high vibration. By this, we restart up again. - 2 nd run: speed just up to over 700rpm. Vibration at ST in acceptance but trip by high vibration at DE of LSS of gearbox and at NDE of pump. But I think that the high vibation of pump is effected by high vibration of LSS of GB. - 3nd, 4 th and 5 th run: Speed up to the same 2 nd run. The pump tripped by high vibration at LSS of gearbox, all other positions is in acceptance. I wonder that why the oil whirl happens at starting up when gear load but not at shutdown time when gear unload as normal (this ussually happened in the past)? Why the restarting at previous time the oil whirl do not happen but it is so much now.