P9801A & P9801B pumping units
are responsible for the circulation of Santotherm 66 (a heating medium typically at an
operating temperature of 296°C). Both machines form part of the C.I.M.A.H regulation 1984
(Control of Industrial Major Accidents Hazards) and are critical to the SHOP PU
Figure 1 - Step change in overall vibration levels.
Analysis of the vibration spectrum indicated a large amount of spike energy along the 2kHz frequency range, from this information several fault types could be eliminated i.e. balance, alignment, coupling problems etc. The information in the vibration spectrum initially pointed to a suspect drive end bearing, however, further analysis of the vibration spectrum would have to be carried out. Once the bearing fundamental defect frequencies had been determined I was able to link some of these frequency values to the frequency peaks evident in the vibration spectrum. In doing so, I identified a fundamental defect frequency of 215Hz strongly suggesting a fault on the outer race/roller of the single row roller bearing at the motor drive end, see Figure 2 below.
Figure 2 - Vibration spectrum indicating bearing damage.
Examination of the original bearings proved the analysis to be correct as several areas of damage were evident on the roller bearing outer race, and also on the rollers themselves. The photograph below is clear evidence of this damage.
Figure 3 - Damage to roller bearing outer race.
Due to accurate analysis and prompt action, secondary damage to the motor components was prevented with an estimated repair cost saving in the order of £20,000.00 and clearly indicates that Machines Talk and it Pays to Listen.