We are experiencing a problem of an overhung pump.
Some facts :
1. The pump is overhung-mounted.
2. There are 2 pumps A/B (1 running, 1 spare)
Histories of Pump A (the one with high vibration) :
1. The vibration was always high from the beginning (5 ~ 7 mm/s peak vs 6.42 mm/s peak)
2. The last repair was to change mechanical seal and bearings.
3. All other conditions of internal parts of pump was good. Wearing rings clearance were good.
4. We ran the pump, the vibration reached 8 mm/s.
5. Since the pump running below its design, we tried to increase the flow to the design flow, but the vibration didn't decrease. It even reached 10 mm/s.
6. The vibration of on vertical inboard and outboard bearings position were high (8 ~ 10 mm/s), while the horizontal position were low (3 ~ 4 mm/s). For comparison, the vibration of pump B were 4 mm/s.
7. The spectrum of vibration at vertical position dominants at vane pass frequency, while at horizontal position there's no dominance at all at vane pass frequency. For comparison, both of vertical and horizontal position of pump B's spectrum shown vane pass frequency as their dominant amplitude.
maybe someone could give me suggestions / possibilities of what happen to pump A?
Thank you.
Vane Pass Frequency Vibration Problem
Re: Vane Pass Frequency Vibration Problem
