This case history involves a $30,000 hydraulic pump and 250 Hp Vertical Motor. This is a pump which had been monitored for several years. Because of production requirements it was necessary to monitor the pump under load each time. The motor and pump are mounted vertically on the top of the hydraulic tank reservoir.
There are 4 data sets to consider. The first from September of 2014,(The Good). This reading was the last “good” reading on the pump, it had been in service for several years. The second from February (The Bad), this reading shows a pump defect with a significant increase in the time waveform amplitude since the September reading. The pump was pulled and replaced with a new factory rebuild. Then from March 3rd, (The Ugly) Shows a significant piston pass frequency which is unexpected in a new pump. The pump was again changed out to another factory rebuild and then from March 11th (The New) shows an acceptable level of vibration.