Forum help

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

@luis

1- where are the historical measurements? They are not included in the report.

2- when the issue has started?

3- cross section drawing for the pump and motor name plate.

4- i think there is redundant (similar) pump, can you please share the vibration report for that pump, including spectral plots.

5- have you checked the piping strain?

I see that you are using SKF software, and i see some unpleasant configuration for the measurements and the report. If you are willing to improve, i can help you remotely to make good configuration.

Feel free to share the requested measurements as SKF. MAB file. 

Regards,

Mohammed 

------------------------------
Mohammed Abdalla

Original Message:
Sent: 03-06-2024 06:14
From: Luis Eugene Tibre
Subject: high horizontal pump vibration dominant at 2x rpm

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

Natural frequency of your system/pump/piping/foundation is near 2x rpm. Your vibration data shows a small "mound" of energy at the base of 2x in horizontal direction, this is and indication that this frequency is close to or at the system natural frequency.

The large ratio of vibration from H to V is also and indication of a natural frequency. With machine running, monitor live time vibration spectrum, tap/strike pump casing/volute in horizontal direction, observe which peak/s rise in amplitude or if there is a skirt that rises and falls as you impact machine

Sounds like you are doing all the right checks/activities, but as you observed the base is in horrible shape on the "inside", looks good on the outside.....the base should have been filled full of grout when originally installed.

The weak base is creating running misalignment. Machine at rest is/could be perfectly aligned, once you start the machine and the base starts moving, the vibration data now shows misalignment/elevated 2x rpm.

Take live time overall or spectral data on the pump base where it is bolted to concrete  Take 10 readings per side the length of the pump base and record the vibration overall vibration, you should expect to see vibration levels of .3 mm/sec or less, if you have other pumps that have a better base or grouted, compare base vibration levels to see how much difference there is between good and bad installation.

Company that makes awesome pump bases if you are looking to replace. Pump bases

------------------------------
Dave Reynolds
www.midlandsrc.com

Original Message:
Sent: 03-06-2024 06:14
From: Luis Eugene Tibre
Subject: high horizontal pump vibration dominant at 2x rpm

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

@Dave Reynolds sir,

        Thank you for taking the time to read all the data and making these input recommendations. i also noticed that mound at the base of the 2xrpm and also considering a running misalignment issue due to the corrosion and no grouting at pump side. We also took reading on the pump feet and the base plate both sides; its pump feet- 2 mm/s and 2.65 mm/s, baseplate- 2.68 mm/s and 2.95 mm/s, base frame floor- 1.65 mm/s and 1.93 mm/s. I will try to learn how to conduct bump test on our skf microlog.

i forgot to mention that when the latest pullout of bearings, there were signs of movement of the outer rings. i was puzzled because when it was brought to the shop, the housing was acceptable.                                                                                                                                 

 Thank you.

------------------------------
Luis Eugene Tibre

Original Message:
Sent: 03-07-2024 08:17
From: Dave Reynolds
Subject: high horizontal pump vibration dominant at 2x rpm

Natural frequency of your system/pump/piping/foundation is near 2x rpm. Your vibration data shows a small "mound" of energy at the base of 2x in horizontal direction, this is and indication that this frequency is close to or at the system natural frequency.

The large ratio of vibration from H to V is also and indication of a natural frequency. With machine running, monitor live time vibration spectrum, tap/strike pump casing/volute in horizontal direction, observe which peak/s rise in amplitude or if there is a skirt that rises and falls as you impact machine

Sounds like you are doing all the right checks/activities, but as you observed the base is in horrible shape on the "inside", looks good on the outside.....the base should have been filled full of grout when originally installed.

The weak base is creating running misalignment. Machine at rest is/could be perfectly aligned, once you start the machine and the base starts moving, the vibration data now shows misalignment/elevated 2x rpm.

Take live time overall or spectral data on the pump base where it is bolted to concrete  Take 10 readings per side the length of the pump base and record the vibration overall vibration, you should expect to see vibration levels of .3 mm/sec or less, if you have other pumps that have a better base or grouted, compare base vibration levels to see how much difference there is between good and bad installation.

Company that makes awesome pump bases if you are looking to replace. Pump bases

------------------------------
Dave Reynolds
www.midlandsrc.com

Original Message:
Sent: 03-06-2024 06:14
From: Luis Eugene Tibre
Subject: high horizontal pump vibration dominant at 2x rpm

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

Hi,

What is the model of bearing for the pump. 

Let's check if the pic at 2xrpm is close to one of the bearing defect frequency. May be external or internal race.

It can be bearing not sitting well with sitting damage

Regards

Serge

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

@Serge Borrell sir,

    There is some validity on your observation because when we pulled the bearings there signs of rotation on the outer ring. However, what puzzles me is that the bearing housing was sent to machine shop and have the housing measured in 3 different points and they said that the fit is acceptable. I attached the image of the pulled out bearings. Bearings are 3310B C3, 6311Z C3. In addition, bsf frequency of 6311 coincides with the 2x rpm. i have attached screenshots of pulled out bearings and spectrum with bearing frequencies. Several times we have replaced the bearings, maintenance said they are using hydraulic press. i have uploade scrrengrab of the velocity spectrum with assigned bearing frequencies and the latest pulled out bearing. What to do next?

Hi,

What is the model of bearing for the pump. 

Let's check if the pic at 2xrpm is close to one of the bearing defect frequency. May be external or internal race.

It can be bearing not sitting well with sitting damage

Regards

Serge

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

Luis Eugene Tibre,

It appears that you may have 60Hz line frequency power. Based on the 1x of 3570 RPM?

Are you 100% sure this 2x RPM is a real 2xRPM  and not  2x Line Frequency? Confirming this with a low Fmax Spectrum, (500 Hz) with  high Lines of Resolution 1600 or 3200 LOR.

A SAFE WAY TO CHECK 2xLF is by monitoring the spectrum and turn off the POWER at the same time. If the 2x disappears, the problem is electrical.

I have done the following I but do not recommend it to anyone: TRY THIS AT YOUR OWN RISK.

Slowly loosen 1 motor hold-down bolt at a time and watching the spectrum in "live mode" to see if the "2x" disappears when any one (1)  bolt is loosened. (But be sure to tighten it back before going to the next bolt).  If 2x LF is the problem (caused by a twisted motor frame, which changes the rotor to field gap clearance),,,, the "2x" will go away or decrease in amplitude when the "soft-foot" is located.

Thanks,

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

Please collect a high resolution spectrum at the same horizontal location (12,000 cpm Fmax with the same resolution you are currently using). That way you will be able to separate 2xTS, 2xFl, and 1xBSF into discrete peaks. 

Also, check phase your base across several mounting interfaces. For instance, pump foot to platform, platform to base, base to floor, etc. Collect at each interface and look for a possible 180 degree phase shift. That would be an indication of a loose mount that is manifested during pump operation. Keep the measurement locations consistent.

You can also determine possible misalignment by using comparative phase across the coupling. Collect phase on the motor bearing in the horizontal direction and on the pump bearing in the same orientation. Look for any phase shifts. Do the same with vortical and axial.

Please do not attempt to loosen mounting bolts during operation!

Please keep us posted!

Luis Eugene Tibre,

It appears that you may have 60Hz line frequency power. Based on the 1x of 3570 RPM?

Are you 100% sure this 2x RPM is a real 2xRPM  and not  2x Line Frequency? Confirming this with a low Fmax Spectrum, (500 Hz) with  high Lines of Resolution 1600 or 3200 LOR.

A SAFE WAY TO CHECK 2xLF is by monitoring the spectrum and turn off the POWER at the same time. If the 2x disappears, the problem is electrical.

I have done the following I but do not recommend it to anyone: TRY THIS AT YOUR OWN RISK.

Slowly loosen 1 motor hold-down bolt at a time and watching the spectrum in "live mode" to see if the "2x" disappears when any one (1)  bolt is loosened. (But be sure to tighten it back before going to the next bolt).  If 2x LF is the problem (caused by a twisted motor frame, which changes the rotor to field gap clearance),,,, the "2x" will go away or decrease in amplitude when the "soft-foot" is located.

Thanks,

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

Luis Eugene Tibre,

It appears that you may have 60Hz line frequency power. Based on the 1x of 3570 RPM?

Are you 100% sure this 2x RPM is a real 2xRPM  and not  2x Line Frequency? Confirming this with a low Fmax Spectrum, (500 Hz) with  high Lines of Resolution 1600 or 3200 LOR.

A SAFE WAY TO CHECK 2xLF is by monitoring the spectrum and turn off the POWER at the same time. If the 2x disappears, the problem is electrical.

I have done the following I but do not recommend it to anyone: TRY THIS AT YOUR OWN RISK.

Slowly loosen 1 motor hold-down bolt at a time and watching the spectrum in "live mode" to see if the "2x" disappears when any one (1)  bolt is loosened. (But be sure to tighten it back before going to the next bolt).  If 2x LF is the problem (caused by a twisted motor frame, which changes the rotor to field gap clearance),,,, the "2x" will go away or decrease in amplitude when the "soft-foot" is located.

Thanks,

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

------------------------------
Luis Eugene Tibre
------------------------------

@Ralph Stewart sir,

    Thank you for taking time to check on my concern.  My problem of concern is at the pump side. Thank you.

------------------------------
Luis Eugene Tibre

Original Message:
Sent: 03-08-2024 22:14
From: Ralph Stewart
Subject: high horizontal pump vibration dominant at 2x rpm

Luis Eugene Tibre,

It appears that you may have 60Hz line frequency power. Based on the 1x of 3570 RPM?

Are you 100% sure this 2x RPM is a real 2xRPM  and not  2x Line Frequency? Confirming this with a low Fmax Spectrum, (500 Hz) with  high Lines of Resolution 1600 or 3200 LOR.

A SAFE WAY TO CHECK 2xLF is by monitoring the spectrum and turn off the POWER at the same time. If the 2x disappears, the problem is electrical.

I have done the following I but do not recommend it to anyone: TRY THIS AT YOUR OWN RISK.

Slowly loosen 1 motor hold-down bolt at a time and watching the spectrum in "live mode" to see if the "2x" disappears when any one (1)  bolt is loosened. (But be sure to tighten it back before going to the next bolt).  If 2x LF is the problem (caused by a twisted motor frame, which changes the rotor to field gap clearance),,,, the "2x" will go away or decrease in amplitude when the "soft-foot" is located.

Thanks,

------------------------------
Ralph Stewart

Original Message:
Sent: 03-06-2024 06:14
From: Luis Eugene Tibre
Subject: high horizontal pump vibration dominant at 2x rpm

dear all,

 good day. i need help. i'm running out on what to check or i may have overlooked some factors. below is the description of the problem

Make up centrifugal water pump: 

  Pump: Paco Pump, size: CL25123, stages: 1 

  Motor: Teco AEHL-WG,90Kw,460V, 3570 RPM, disc coupling type

Symptoms:

• High directional vibration specifically on horizontal on pump

• Dominant 2xrpm ,4hv-1358%,3hv- 171.7%

History correction made:

• Alignment check and correction (several times already)

• Shaft deflection check with noted 0.05 deflection on both shaft end impeller and coupling side (accepted)

• Housing tolerance and eccentricity check (sent to shop and corrected)

• Pipe stress/alignment check (acceptable)

After these inspections and corrections, we are looking into possibility of Type B looseness due to rocking motion or cracks

Initial inspection done:

• Check of pump base bolt- observed not penetrating the baseplate flooring, so we attempted to replaced with longer bolts. However, we discovered that the base flooring hole is tapered and the longer bolt cannot get through. We just measured manually the total height (pump feet thickness+ basebolt plate thickness) if matches the length of the bolt to verify that the whole thread is engaged with the base plate and end up returning the original bolt. (Figure 1)

• We observed that the base frame is also corroded. However I am not sure if it is main factor to the vibration since the base plate and the anchor bolts are still intact. (Figure 1)

• Measure vibration on discharge elbow pipe, 9mm/s

Thank you very much.

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Luis Eugene Tibre
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