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Asset Condition ManagementPosts About vibration/alignment/balance
overall value and frequency peaks
Registered Member Jonh is correct, overall value means min-max between a the frequency span of the waveform. Afaik, on ams you have to choose from digital or analog integration, so the overall value comes either from the "waveform" signal "true peak" or from the sum of the spectrum peaks RMS. [ more ]
Registered Member You might want to review the thread at what does 'pk' mean to you? . Specifically review my comments on page 2 of the thread that are presented in response to Reply #18 (page 2) that "Curran919" on posted Apr 12, 2018. I took the peaks from his presented data and showed how they are summed to approximated the overall value. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
2140 AMS communication error
Registered Member Mike, Do you have the same number of data collectors as laptops? I have found that AMS software, single user, vibe silver, windows 10, will kick out errors if I have the same serial number software on a separate laptop running at the same time connected to a network via blue tooth during data dump I always build route in VA tab and load via data collector 2140 on data transfer tab using 2140 to control, if any changes are done to any database you need to go to VA tab and select the dbase... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
30x vibration on a 6 vane scrubber fan?
Registered Member This is something else I can plan to do when I can get production to take the asset down again. As with most places I have to wait for a planned outage on this asset circuit to do jobs that require taking the asset down. Thank you for the suggestion [ more ]
Registered Member Can you collect cascade plot during coast down & see what happens to that 30X. collect the data from where u see highest amplitude. if u have a 4 channel type then you can collect H & V direction on both DE & NDE bearing [ more ]
Registered Member Nothing significant imo [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Vibration variation in reciprocating compressor at various speed
Registered Member This vibration is new? I mean, is this a new equipment? Or is a new problem in an old one equipment? [ more ]
Registered Member Vibration-Speed sensitivity is probably related to flexible/resonant motor base. Motor rotor and sheave/pulley unbabance and possibly sheave/pulley misalignment contribute to the driving force at 1x motor speed. Make sure you have good spectrum frequency resolution, since 2x compressor speed is close to 1x motor speed. Increase frequency resolution or conduct time-synchronous averaging with a 1x motor speed tachometer signal, if there is any doubt. Inspect motor base for loose bolts and for... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
5X vibration in Integrally geared Elliott compressor
Registered Member Shans, When I do the frequency calcs I get 149,558cpm for 5x pinion A if your motor is at 3,000rpm. To get 142,500cpm the motor has to run at 2920rpm - could you confirm that speed? If the motor is not running at 2920rpm then the frequency you are seeing is not 5x pinion A. The reason I mention this is that the most common frequency I see that indicates gear tooth profile deterioration is not gear mesh frequency but the natural frequency of the gear. If you get the opportunity I suggest you... [ more ]
Registered Member I noticed that your unit of measurement is mm/sec. Are you using an accelerometer and integrating back to velocity? If it is an accelerometer do you take the DE and NDE readings with the same transducer, or are these two separate and permanenty mounted transducers? What is the make and model of the transducer? [ more ]
Registered Member What type of coupling is being used How many blades on turbine wheel Do you have any details about the oil pump for this machine? Gear driven or electrically driven, type of pump Dave [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Motor Stray current /magnetic flux measurement
Registered Member Why would you choose an oscilloscope instead of a vibration analyzer? I use a CSI 2120-2 along with clamp-on current transformer (homemade resistor box), CSI Flux Coil, and CSI Shaft Stray Current Sensor. Not much use of the shaft rider current sensor, since shaft access is often limited, and it can be dangerous to use. SKF makes a noncontact electrical discharge detector pen (EDD pen). Here are some searches and references that may be of value: Search: motor flux sensing coil... [ more ]
Registered Member Greetings Dave , both are very expensive technologies . [ more ]
Registered Member https://empathcms.com/ and https://empathcms.com/category/technology/ https://www.artesis.com/products/emcm/ Couple of products I am aware of that may help Dave [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Looseness like spectrum with severe impacting in centrifugal fan
Registered Member Greetings Ikram Patel , As per your inputs i understood that 1.Motor soft foot /mechanical looseness present in your equipment .So that your impacting decreased when hold down nut bolts tighten & still you have looseness because of jaw coupling with spider clearance might not sufficient .Until unless readings are with in satisfactory condition , need not worry & keep monitor trend . [ more ]
Registered Member Please post the data after the locknut had been tightened. [ more ]
Registered Member Maintenance team have tightened locknut, now no impacting seen in waveform, however looseness like symptom still present. @Registered Member- phase data dis not collected, will plan and update for the same. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
asymmetric stiffness effect on vibration
Registered Member Dear Gents thanx for you valuable replies, problem is solved by the following steps: 1- bump test was done again using force hammer (FRF) and we found that the natural frequency is 51.4 hz which is very close to 2x peak (49.8 hz). 2- the big question was about the sudden increase in vibration values specially in axial direction. 3- we decided to check the stiffness of the system by checking the bolts tightening at first and we found many bolts were loose. 4- after retightening the loose... [ more ]
Registered Member Walt suggests a source for 2x, a rotating assymetric stiffness; 2-pole electric machines often have 2X as a result. You need to give more details, including what the thought is regarding misalignment and its connection to stiffness or other. If one were to preload two shafts through misallignment then asymmetries 2-pole motors, keyways, other can result in 2X. Amplification through a natural frequency could result in high axial vibration, but you indicate that this is ruled out by a bump test. [ more ]
Registered Member I'm not able to imagine the mechanical system. Perhaps, a layout sketch or a picture from the internet would help to understand the problem a bit better. Can you post some of the collected vibration plots? Sometimes, when data is read by others, they interpret it differently. Regards- Ali M. Al-Shurafa [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
poor repeatable result of alignment device
Registered Member My idea is any method of measurement should be stable and same for a given system, comparing two systems is good. You could do a test on a Ridgid shaft (steel pipe will work), install your head setup an alignment and rotate, it should be zero. [ more ]
Registered Member just to inform, i change mode to Multipoint ( like 3 9 12 hour orientation ) i am pleasure with its result...it is repeatable and crosscheck with SKF device and match . Thanks for all. [ more ]
Registered Member Thanks fburgos. Yes ...u r right and absolutely right . [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
High Vibration in Elliot Compressor
Registered Member @Registered Member Thanks. I have posted my case https://www.maintenance.org/topic/498273567791355211 [ more ]
Registered Member SHANS, Vibrant has not been on the forum in about a year. I suggest you review the previous related content and then post specific questions and data relative to your machine. [ more ]
Registered Member https://www.maintenance.org/to...4#399590942964619454 Hello Vibrant, I am facing similar issue in our elliott compressor. Speed is around 28K cpm and dominant vibration around 5X. What was your final conclusion in the above case? [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
what is better: resonance or high stiffness
Registered Member Agree higher frequencies and impacting will be there to catch developing defects. I was thinking if someone is passing around those hypothetical machines, the resonant one you will know right away something is bad [ more ]
Registered Member Ferdy, perhaps not necessarily. Structural resonance typically takes place at low frequencies. Masking the unbalance deflections by stiffening will not mask higher frequencies (like bearing faults). But I agree that stiffening a machine (say a vertical motor) will reduce the measured vibration but it will not reduce the unbalance force. Some failures from the resonance or unbalance forces like structural cracks, looseness in instrumentation, etc will for sure be reduced by stiffening the... [ more ]
Registered Member Yes, I would assume the bearings last longer in resonance, since the force exerted on the bearing is lower. Oke, resonance is also bad for fatique and maybe some electrical issues as well. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Vibration analysis software
Registered Member Recently changed to Acoem falcon from Skf na during I would highly recommend it. Good support some nice advanced features my old kit didn't have and also no recurring fees bar calibration recommended every 2 years. also triaxial wireless sensor that collects one block of data and post processes it and can do additional post processing tomte data once collected, greatly speeds up data collection on regular routes. [ more ]
Registered Member Emerson CSI user, Great software, good box, almost too expensive to maintain, the calibration fee is 3-5x times expensive than other vendor, every year you need a support agreement if you want to keep updates and fixes, I think if you save for all this support agreement in 5 years you could easily spend the amount on a new system of another vendor. If I could start again I would pick another vendor, acoem or adash for example they looksvery nice, I'll try to get a loan unit or "tests drives" [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Radial Vibration Probes reading keyphasor
Registered Member By indexing I’m referring to maintaining the coupled machinery in one angular relationship casing to casing. Is it absolutely essential, “No”. Can it be helpful at times in understanding machine behavior, “Yes”. And generally it is something relatively easy to accomplish. [ more ]
Registered Member Dear John Thanks again for the inputs. As for your point regarding solorun of Turbine or Compressor is concerned, what I mentioned is possibility of Compressor & Turbine Shaft coupled in different angular orientation before and after maintenance due to any of following scenarios that I have seen For DryGas Seal Replacement, once Coupling Hub is removed Compressor Shaft is normally turned to bring Dry Gas Seal drive pin or keyway for drive key into correct position relative to Seal... [ more ]
Registered Member If you have done this on turning gear, you could remove power from the shaft trigger signal to check. As to exceeding the DC limit for the OK check, I don't see this. DC values on a dynamic signal are likely obtained through a low pass filter. Ideally, this would give the same value for DC as a Fourier Transform (series) where the DC value is the time average. A scratch tends not to have a large effect on the average voltage, which is the DC value. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Half X much higher than 1X
Registered Member I have seen many times in vertical pumps that 1/2X is related to pump bearing wear. Perform motor solo run and see if vibration levels goes down. [ more ]
Registered Member Thanks guys. Very helpful. I will take these notes with me next time i go on the location. I did listen to the NDE and DE bearing with Ultrasound but nothing special there. This is Velocity FFT where packing is ( near pump ) Very low amplitude there I know but maybe source of problem can be seen there. Most of the spikes are related to 1X. Quite strange this peak, I have suggested to the owner to monitor it more frequently. [ more ]
Registered Member Good job for you Have you ever check the input strainer ? According to your data it can be source of flow induced vibration Best regards [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Harmonic reject/Elimination filter
Registered Member @Registered Member thanks [ more ]
Registered Member No problem, if you ever want those peaks back just press "G", if you use Vibration analysis tab press Ctrl+H a hotkeys dialog is displayed. Here is a printable version I have in my desk. https://docs.google.com/spread...pof=true&sd=true If you use plot data, many of them will work, and in the toolbar there is an icon that bring up the hotkeys too. [ more ]
Registered Member Thanks @Registered Member, it's working well [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
MOTORS ENVELOPE VALUE HIGH WITH TEMPERATURE & NOISE
Registered Member Greetings Sir , it is a V.F.D operated motor and it is running at 23.75 Hz .Velocity vibration readings are with in limit . MOTOR 2 MOTOR NON DRIVE END MOTOR DRIVE END HORIZONTAL VERTICAL AXIAL HORIZONTAL VERTICAL AXIAL ACCELRATION 1.81 2.5 0.73 2.16 1.71 1.3 DISPLACEMENT 24.43 22.67 23.87 24.78 24.31 25.05 ENVELOPE 0.93 1.16 0.3 1.2 1.06 0.66 VELOCITY 2.23 1.88 1.77 1.65 1.5 1.54 MOTOR1 MOTOR NON DRIVE END MOTOR DRIVE END HORIZONTAL VERTICAL AXIAL HORIZONTAL VERTICAL AXIAL ACCELRATION 2... [ more ]
Registered Member Kishore, What kind of "Noise" do you hear? A "beat" or a constant noise with no variation? Looks like Line Frequency might be 47.5 Hz rather than a full 50 Hz, base on the slip frequency being produced by the VF Drive system, showing in the spectrum on page 1. The tall peak, close to, but not quite at, 100 Hz appears to be 2xLF (95 Hz) caused from the VFD and the "harmonics" of 2xLF seem to be getting farther away from the, 100 hz, 200 Hz, 300 Hz Etc. frequencies which would be a true... [ more ]
Registered Member A lot of harmonic of shaft speed, also small peaks around what it seems to be line frequency, any normal FFTs [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
how to check the sensitivity of rotor balancing system with a rotor
Registered Member Dear Forum members, Sensivity check of balancing machine with rotor. This is mentioned in ISO-21940-21:2012 in detailed procedure but i don't have the procedure and do not have any idea how to perform this check .Request any one who is aware of this procedure can explain in detail. The standard old version is ISO2953 and regarding this procedure i found one image attaching for your reference. Ravishanker [ more ]
Registered Member I have used Excel for polar plots of balancing, dial indicator and ultrasound data. I found that using the Radar plot with at least 8 data values is visually suitable. John's reference link looks handy for this method. I have found two "tricks" on occasion that helped. 1) Rescale the data, as needed for visual appearance 2) Overlay a circle (I use Bluebeam Revu) to find circle center of data and variation from mean value. There are sources on Internet for Excel add-on for Polar Plots. [ more ]
Registered Member Some guidelines on developing a spreadsheet generate a circular plot can be found at https://peltiertech.com/polar-plot-excel/ [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Data export from AMS Suite Machinery Health Manager
Registered Member I use the reporting tab, with "report" I made, now I ha ve version 6.3, I'm sure previous 5.7 also had a reporting tab. [ more ]
Registered Member Ohh Great, could you share with me how do you export to excel or csv? [ more ]
Registered Member You can export to Excel, CSV I use it to feed a "excel database" for reporting [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Isolator condition check point
Registered Member I think your problem is couple unbalance. One advice, use a bubble chart, place your R eference accelerometer on a medium vibration point, for example MIH, don't move it, just move around the other sensor to record phase and fill the buble chart. Here is an example of a bubble chart. https://ludeca.com/blog/condit...le-collecting-phase/ Use procedure above to record bottom and top of each isolator. [ more ]
Registered Member No, I don't mean floor vibration. it is measured on support structure just top on rubber isolator. For your reference I attached fig. 1 with arrow showing measurement location. we have same blower except power transmission element. in my case impeller is directly fitted on motor shaft. organization does not allow me to take photograph. hence, I can not upload real photo. We have taken phase on motor bearing. refer attached image for phase data. [ more ]
Registered Member Subsynchronous, the natural frequency of the rubber should be below frequency of rotation. So you say the floor has 12mm/s? Could you post a diagram with the phase data, beside/under isolator (floor) on/above isolator (machine frame) [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
High Vibration Centrifugal Slurry Pump
Registered Member It is either design/mechanical in nature or process related, when all 6 have same issue it could still be either of these scenarios, but leans more towards process issue, is this a new installation or existing, why now are you concerned of issues, did this issue just appear. Is the machine driven with a VFD variable speed drive? Is this strange vibration present speed dependent, as the vibration decreases if you slow down or speed up the pump? Have you verified no entrained air in top of... [ more ]
Registered Member We rule out problems associated with couplings as we frequently check alignment and condition of couplings and grease. The other pumps that I mentioned previously have the same configuration and same issue (Strange frecuency vibration with harmonics sometimes). From the operational point of view the pump does not present problems of flow or pressure, however in the inspections by condition monitoring this anomaly is detected and for the moment we keep it in follow up, but we need to... [ more ]
Registered Member M6 Nils, On the vibration analysis tab of your AMS software, select the specific time/date of the waveform you want, on the right hand side of the plot there are icons, the icon with a speaker, selecting this opens a "wav" player, you can save the wav file and post, that adds value to this discussion. Pumps can be fickle, this style of pump I usually see in slurry applications. Things that can make a pulsating noise from my experiences: worn/dry coupling, loose mechanical tolerances to... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Allocate extra Vibration data collection time for "Resolution" or "Averaging"?
Registered Member Thanks @Registered Member In your opinion, will the noise in the following modes give us a different form of FFT(different form of noise floor)? 1- Figure A: Four Averages of FFTs with resolution 4 Hz (250 ms Time Signal length) 2- Figure B: One FFT with resolution 1Hz (1000 ms Time Signal length) [ more ]
Registered Member It's commonly accepted that randon noise will hide small amplitude repetitive signal, the average usually takes place in the FFT it averages down the random noise floor and the repetitive signal is keep. The waveform "resolution" is inverse of the spectrum resolution. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Beat vibration on a FEDCO multistage MSS Series High Pressure Feed Pump
Registered Member Harout80, Can you show a couple of different velocity positions' high resolution spectrum and waveform plots from the motor (MIH) and (MOH)? Do you have the tools to taking a Peakvue (CSI) or demodulation spectrum data with high resolution and with a high pass filter of 1K Hz and 2K Hz? Or whatever your system has as a High Filter choice nearest the 1K and 2K? What is the motor speed? Thanks and Have a Great Day, Ralph [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Resonance on 4-Stroke Diesel Engine Fire Pump
Registered Member Hey All, Just for update, we already solved the issue. the problem was on the coupling (Looseness on the hub), after we change the coupling (Hub + Rubber) the vibration drop to 5 mm/s. we also add more stiffness on the horizontal direction to make sure there is no problem from resonance. Best Regards, Java [ more ]
Registered Member Hi Dave, The pump suction is from the tank. for the base, same type no grout just metal base. we not considered thermal growth for this engine, actually we don't have experience to calculate thermal growth. only if the OEM noticed us about the thermal growth then we will add thermal growth yes the vibration is very directional (Horizontal) on the engine, we did re-alignment after modification, We eliminate suspect from pipe strain because the vibration only got high on the engine only... [ more ]
Registered Member Java, More details needed: how does the pump suction get water to the pump, tank? suction lift? Is the base under smoother running pump 5 mm/s rms grouted? Is there any thermal growth added to alignment? Is vibration directional, like only horz is high, I see 2x rpm increased after modifications, did you realign after your modifications? Vibration increasing overtime and other pump running smoother are clues. Thermal growth is one scenario that would cause vibration to gradually increase. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
odd frequency 82 Hz observed on the 13 MW TG set assembly
Registered Member OK Thx John, will recommend to the OEM accordingly & will wait for their response. Thx again for all your inputs & support. Cheers [ more ]
Registered Member “Yes” lots of oil moving around in the gearbox but that is why I mentioned “hard bluing”. In the States what is commonly used is a product called Dykem Steel Blue Layout Fluid. It comes in various forms like an aerosol can or a brush on product. The teeth have to be cleaned really well in the area where the bluing is sprayed. I have also used an “orange” colored product and personally don’t like it. The blue colored product is much easier to see in poor light. This is what is commonly done... [ more ]
Registered Member Thx John. But once the gear is under load there will be lot of oil flushing taking place inside which may wash away the applied blue. Just thinking...???? also if we record the vibration data with lower loads & also with load removed. This will give us some hint on what's happening to 82 Hz, will it stay or disappear. just a thought.... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
High vibration @ Boiler feed water pump
Registered Member Greetings. I would like to also ask if there is a phase marker with the 1x vibration. During the period after a load increase, where the flow is reasonably steady, is there a phase shift associated with the "slow" vibration increase? Are the DE and NDE bearing vibrations in-phase or out-of-phase (of in-between)? Lyle [ more ]
Registered Member the pump has balance line? in case it has is possible that you have recirculations problems with this element, normaly the problem cuases when you increasse the load [ more ]
Registered Member I would test for natural frequency with pump running at low and high load to see if the natural frequency changes due to change in pipe support stiffness. The impact-response vibration method with negative averaging could be used. Consider installing a temporary ultrasonic flow meter on discharge pipe exterior to confirm flowrate at different load operating points. You might find that Pump-C flow is below BEP point evan at higher load, assuming there is another pump operating with it. Walt [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Bearing or Eccentricity
Registered Member I have downloaded pdf attached file that named was PUMP 11 DE bearing [ more ]
Registered Member First and second are Demodulation spectrum DE bearing ( 500-16k ) Then Velocity DE bearing ( no harmonics ) Last is Acceleration spectrum NDE and DE [ more ]
Registered Member I saw your 1x was 24 hz.didnt it? But if that was your 1x harmonic you should see them on fft [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
fluidizing blower high horizontal vibration(what else can be done, running out of ideas?)
Registered Member I see in the FFTs 2x and 3.*X in the blower, no one else? I've seen this blowers and manual said the bolts over the antivibration pads should be loosen. Re tightening could change the shaft alignment, the discharge side gets very hot, and the alignment is different if the discharge is inboard or outboard. [ more ]
Registered Member hi, we know this "solution"! I think it depend af an incorrect distibution of damper or external force by pipe or unplane floor. we tried to put a thickness between dumper and chassis. [ more ]
Registered Member Good day every one. i just want to update that we already manage to reduce the high horizontal vibration of the blower by simply loosening the overtightened bolts of the newly installed vibration pads. may this case a reference for every one in the future. Thank you all for taking the time to respond, sharing of ideas and experience. @Registered Member @Registered Member @Registered Member @Registered Member @Registered Member @Registered Member @Registered Member [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Low Speed Bearing Analysis - What is possible?
Registered Member Thank-you Walt and Vic. Your learned and timely responses are very much appreciated. Tony [ more ]
Registered Member So, that's what this is. Well, if the downtime cost justifies the investment, then so be it. [ more ]
Registered Member "WWII oil flooded recip's once in China and the old earth quake (ball & pivot) mercury switches provided sufficient protection >99% reliability for 50+ years." Does this indicate the vibration switches detected every machine fault/failure, or there were no machine failures, or the switches never activated (including no earthquakes) in 50+ years? I am proactive with my wheelbarrow (garden carts) by keeping the bearings lubricated. The mining machine in the OP probably has a greater... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
High Vibration in 1X in vertical seal oil pump
Registered Member So H is taken 90 degrees to piping and V is taken inline with discharge pipe? Is this a new installation or existing? How does the base plate anchor inside the housing? I see a square plate, is the pit/housing also square? Highly unlikely an outer race fault would create this level of vibration, acceleration values would be high if bearing was bad Any recent maintenance activities? Pipe strain, mounting plate not properly anchored, assembly errors What type of coupling? Is pump flow and... [ more ]
Registered Member Hi John, i got your point. let me show you our pump, as attached, this is emerged pump with oil filter in discharge. We have 3 pumps were installed with same design ( copy past ), but we don't have this issue. what do you think ? is it excessive clearance between outer race and housing ? Regards Anis [ more ]
Registered Member You totally missed my point! Vertical pumps are often stiffer in one direction due to the external piping, the discharge line for instance. A transducer is often mounted in-line with that piping and the other of course at 90 deg. I do not know what X or Y mean (horizontal or vertical) with respect to your pump. In the attached graphic note that the "Y" is in line with the piping. [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
I.D Fan strange Balancing response
Registered Member " I see by one of the provided spectrums the 1X (975 cpm) is about 2.45 mm/sec for the same measurement point. The overall is 6.072 mm/sec and there is a substantial amount of higher frequency above 5 kHz." That is why I questioned the value of balancing! Some of the OP numbers could be filtered 1xSS or overall levels. I will wait for the OP to clearify the balance numbers with 1xSS amplitude-phase and overall level for each measurement point and each configuration. Walt [ more ]
Registered Member Walt, I'm seeing numbers in the tabulated data that are in excess of the "...very low before balancing (highest was 4 mm/sec or 0.16 in/sec)" that you mention. In the initial run I'm seeing 7.93 mm/sec in the "FAN N.D.E HORIZONTAL". In addition, based on the provided data, that likely is mm/sec RMS. 7.93 mm/sec = 0.31 in/sec and if we bump that up it is 0.44 in/sec peak. The data seems very erratic as well. I see by one of the provided spectrums the 1X (975 cpm) is about 2.45 mm/sec for the... [ more ]
Registered Member Filtered vibrations levels at 1xSS were very low before balancing (highest was 4 mm/sec or 0.16 in/sec). The 1xSS was not the dominant frequency in velocity spectra, so it has minimal affect on the overall velocity levels. Why are you doing balancing? If you must do balancing, then why not do a single plane solution for only Plane 2 that had roughly 3x higher vibration level levels and similar phase to Plane 1? If amplitude and phase are changing a small amount, then averaging would help... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Cement Plant Air Separator Bottom bearing Condition Monitoring
Registered Member if the lower support is fixed with tie rods (four crosses), on these you can measure the vibratory state and peakvue with CSI instruments. the values are always very muffled, you must note the tendency to increase (at the same speed). in my opinion, the best thing would be to check the fat output. the labyrinth grease is disposable but the bearing grease should be captured and taken out with a tube. these pipes (supply and drain) must be insulated otherwise the dry grease forms a plug [ more ]
Registered Member Because we all know what is a "sks separator".... this is an very old post [ more ]
Registered Member Cement plant professionals can achieve a predictive and proactive maintenance strategy with the help of real-time data from online condition monitoring systems. Cement plant condition monitoring can reduce the time-consuming field work, the plant can count on precise measurements, increasing the reliability of failure detection and consequently the availability of plant equipment. The following cement plant equipment can be monitored with condition monitoring: Monitored Equipment Vertical... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
Lobes Compressor (A headache!!!)
Registered Member Mr. CJ,You apear to be a sales person who has offered nothing of technical value to an old discussion! Walt [ more ]
Registered Member We offer blowers and pneumatic systems. You can see more info here: https://www.palamaticprocess.c.../pneumatic-conveying [ more ]
Registered Member HI Reliable Analyst, Can you share root cause of your compressor high vibration if it was solved ? Regards Imran [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
bearing failure analysis on a 900hp compressor motor deep groove bearings
Registered Member I was about to raise same thing Ralph related to obstruction of topic. It would be better to cut the cage and see the inner ring surface as well. IMO, It seems like abrasive wear due to inadequate lubricant and would be ended with spalling if allowed to run longer. Excessive axial load didn't allow lubricant to perform as it supposed to. Suggested lubrication frequency and quantity would be suitable for design load. However, Installation of asset, operations and behavior of the driven... [ more ]
Registered Member Looks like there was a tremendous axial load being applied, causing a heavy, 360 Degree contact with the outer race. Why are the pictures obstructed by the Topic definition? Thanks, Ralph [ more ]
Registered Member Thanks for the closeup pictures. Unfortunately they are not really sharp so hence difficult to see exactly what you describe in your text. You might want to review the document at Bearing damage and Failure Analysis [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
The sawtooth vibration behavior occurs after steam turbine running up to normal speed
Registered Member I have attached Exhaust Temperature & Inlet Steam Flow Curve of a Single Stage (Curtis) Back Pressure Steam Turbine where effect of Governor Valve movement on Exhaust Temperature is more evident. [ more ]
Registered Member Hello lux You have mentioned no obvious relation with Differential Temperature b/w Upper & Lower Casing and also you have mentioned Casing Temperatures of 400-410 Deg Celsius. May I ask how Casing Temperature is measured ? You have mentioned current behavior is not related to Process Loading. May I ask if the Turbine Inlet Steam Flow remains constant from the time Vibration fluctuation starts till the time it is vanished ? During Startup Temperature within Steam Turbine changes sharply... [ more ]
Registered Member Hello Dear All- Thanks for your kind comments above. For the casing expansion----Actually this was measured duirng the commissioning (at the beginning of this year), didnot find an uneven expansion from the readings of several dail gauges at that time. Also as I mentioned above, the vibration behavior is not related to starting mode. Even for hot start ( Time interval between shutdown and restartup is less than 1 hour), the temperature of casing compared to normal operting basically was same... [ more ]
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Asset Condition ManagementPosts About vibration/alignment/balance
what is insensitivity check as per API
Registered Member I don’t think there is anything that API defines as an “insensitivity” test. Can you site a link that uses that terminology? [ more ]
Registered Member Dear Sir, Earlier i asked about sensitivity test, But now it is insensitivity check, can any tell which clause no. in API or explain in detail. Ravishanker [ more ]
Registered Member It isn’t “insensitivity” check, it is sensitivity check and you asked the same question back in April. See https://www.maintenance.org/to...-system-with-a-rotor For the responses from back then. [ more ]
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