Pl. see attached spectrum. We can see a lot of activities going on between 10 to 50 th orders of running speed on pump NDE brg. What it may be ? Lack of lubrication? Random noise. None of the peaks was found maching with bearing defect frequencies.

Hi Akthar,

Some more questions...

Is this pump sounds like cavitation(like gravel passing through the pump)? Is it a vertical pump?Do u have an anti-friction bearings or just a bush type?

By the way, why you are bothering about a 0.99mm/s vibration level? Is it high in the acceleration spectrum?

Have a nice day!!

Jenish, This is from a vertical pump. Not worried about the amplitude , just curious as to what can cause such noise or broadband vibration? The pump is not cavitating. Accln is also low. Only 0.263 g RMS overall.

Hi Akhtar,

What type of bearing you have in the NDE?

If you have an anti-friction bearing there, you can check whether it is a lubrication problem or not by applying small amount of grease and monitor the change in the signature..A change in signature indicates a lubrication issue but make sure the noise floor is not coming back after some hours of running!!

Have a nice day!!

AKHTAR,

Could you please post the TWF in g's?

Is data actually taken on the pump NDE or on the motor?

looks like cavitation or recirculation to me, does this pump have inlet and outlet valves that are not fully open? or possibly debris built up on the impellor?