Dear Mr David, Kindly find the below information to solve the abnormal sound in vacuum pump,We have followed the start-up procedure as given in manual Eta document no.   60998/020 Rev 1 (Pre-commissioning and Commissioning Procedure)The referred drawing for line-up of start-up activity is PEP43001-2, Rev 2  How much of the pre-commissioning and commissioning checks have been completed, it is important that these are signed off and properly completed before moving to the next activity.

(All the pre-commissioning and commissioning checks are completed.)

Please provide site pump/motor alignment checks done as part of the commissioning.

(Motor/Pump alignment checks completed as part of pre-commissioning activity)

Please confirm that the couplings have been correctly reinstated after alignment.

(Couplings reinstated after alignment)

Running current drawn to the vacuum pump motor drive

(Current drawn --------130A.)

Vacuum pump and motor bearing temperatures – if you do not have the exact temperature have you noticed if the temperatures seem excessive.

(Not exceed as the Motor No load and during pump run test, bearing temperatures of pump and motor are normal.)

Which package and which pumps you have tried – are you having the same experience with all of them?

(We have tried the Pump P-1410 & P-1400.) Both are making sound during start-up.

Confirm the actual D/A Feed water temperature.

Ambient temperature -     31 C

Confirm the Vacuum Pump Seal water temperature measured at TI1400 and if possible the water temperature in the separator – this allows us to confirm the seal water flow is about right.

TI-1400 ---30 C

Confirm the D/A Feed water flow rate

Feed water flowrate to Tower B...    800-1000 m3/hr

Confirm the Vacuum pump seal water flow rate

Seal water flow rate--------- 9.5 m3/hr -12 m3/hr.

Confirm the Status of all actuated valves on the skid – is the pump on line to the DE aerator vessel and ejector on lineConfirm the Are the motive air inlets to the ejector open – XV1370 and V92/V93

Yes, valve open as the pressure in the tower B reaches 100 mmHg.

Confirm the Stage pressures achieved

Top stage pressure last time achieved -71 mmHg.Bottom stage pressure last time achieved- 19mmHg. (ie required in normal operation).

During the start-up we found some observation which I want to share for solving the issue.

Before start-up we have set the seal water flow at 9.5 to 10 m3/hr. We observed the level in de-oxy separator normal as up to the centre of pump casing.

After confirming seal water flow we started the pump and within 5 sec, we opened the vacuum line shutdown valve by force. Pump runs smoothly for a minute, vacuum was coming in tower B. But we found the pump’s suction bellow squeezing and after than abnormal sound of pump started from casing then we stopped it.

Kindly let us know about the PVSV installed in suction line of pump.