This is a motor pump combination machine and its speed is 1480 rpm.

This machine is not in our routine vibration surver list.

Recently this machine was overhauled. When started, it had an unusual noise.

We were called to take vibration readings. Ther overall were well within the acceptable range, however unusual noise can be heard.

I am attaching motor outboard horizontal & pump outboard horizontal spectrum & waveform.

Please suggest. . . .

Waste_Water_Recovery_Basin_Pump.doc (108 Kb, 53 downloads)

Zee-vibe,

Retake data at Fmax=1000 HZ with better resolution ( 1600 lines) . Also take additional data with Fmax=2500 HZ. Put some cursors on the plots.

David

Do solo run of the motor. Find noise is from pump or motor. If found in motor, the first thing to check is bearing mounting and lubrication (I hope lubrication,you might have already checked.) DE side bearing may be cylindrical roller bearing. May be due to lack of preload , rollers might be skidding. Numerous guesses. But , first solo run.
Regards.

Zeeshan,

If the vibration level is acceptable and the spectra does not indicate unusual profile then, I would do a walkaround the unit to check for any loose metal/material that may be resonating and causing the noise.
In one case that I was involved, the mechanics were on the verge of tearing a vertical recip unit to replace the main bearing because of intermittent high pitched noise that seem to be coming off the bearing area. It was a metal instrument tag on a thermocouple gauge on the discharge piping that was ringing whenever the machine started to load.

P.S. What's the present status on Pump "B" vibration problem??

Regards....Rajan Muthukrishnan

Maintenance department changed the material of the bushes. I think that can damage and make noise.

Sorry Akhtar, cant perform a solo run as the machine is already been dismantled and taken to the mechanical workshop.

Rajsha,

As far as the Heat MEdium Pump is concerned, the answer will be avaiable on its Q/A page....